Herbicidal 3-thio-5H-imidazo[2,1-A]isoindole-3-(2H),5-diones

ABSTRACT

This invention relates to novel thioxo-2-imidazolinyl benzoic acids, esters and salts, a process for the preparation thereof and a method for the control of undesirable monocotyledonous and dicotyledonous plant species therewith.

This application is a continuation-in-part of Ser. No. 519,615, filedAug. 2, 1983, now abandoned.

This invention relates to novel thioxo-2-imidazolinyl benzoic acids,esters and salts, a process for the preparation thereof and a method forthe control of undesirable monocotyledonous and dicotyledonous plantspecies therewith.

The invention relates, more particularly, to herbicidally effectiveformula I, thioxo-2-imidazolinyl benzoic acids, and their esters andsalts; formula II, 3-thio-5H-imidazo[2,1-a]isoindole-3(2H),5-diones;formula III, 2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-diones; andformula IV,1,9-b-dihydro-2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-diones, depictedby the following structures: ##STR1## wherein R is hydrogen; C₁ -C₁₂alkyl optionally substituted with one of the following groups: C₁ -C₄alkoxy, halogen, hydroxyl, C₃ -C₆ cycloalkyl, benzyloxy, furyl, phenyl,halophenyl, C₁ -C₄ alkylphenyl, C₁ -C₄ alkoxyphenyl nitrophenyl,carboxyl, C₁ -C₃ alkoxycarbonyl, cyano or tri(C₁ -C₃)alkylammonium;

C₃ -C₁₂ alkenyl optionally substituted with one of the following groups:C₁ -C₃ alkoxy, phenyl, halogen, or C₁ -C₃ alkoxycarbonyl or with two C₁-C₄ alkoxy groups or two halogen atoms;

C₃ -C₆ cycloalkyl optionally substituted with one or two C₁ -C₃ alkylgroups;

C₃ -C₁₀ alkynyl; or,

a cation, as for example, alkali metals, alkaline earth metals,maganese, copper, iron, zinc, cobalt, lead, silver, nickel, ammonium,organic ammonium, or the like;

R₁ and R₂ each represent C₁ -C₃ alkyl or cyclopropyl, with the provisothat the sum of the number of carbon atoms in R₁ and R₂ is 2 to 5; andwhen R₁ and R₂ are taken together with the carbon to which they areattached, they may form a C₃ -C₆ cycloalkyl ring optionally substitutedwith methyl;

A is hydrogen, hydroxyl, C₃ -C₆ alkenyloxy, C₃ -C₆ alkynyloxy, C₁ -C₆alkylthio, NR₁₃ R₁₄ or C₁ -C₆ alkoxy optionally substituted with phenyl,halophenyl, C₁ -C₃ alkylphenyl, C₁ -C₃ alkoxyphenyl or di-C₁ -C₃alkylaminophenyl;

R₁₃ is hydrogen, C₁ -C₄ alkyl optionally substituted with phenyl,halophenyl, C₁ -C₃ alkylphenyl or C₁ -C₃ alkoxyphenyl;

R₁₄ is hydrogen or C₁ -C₄ alkyl;

X is hydrogen, halogen or methyl;

Y and Z are each hydrogen, halogen, C₁ -C₆ alkyl, C₁ -C₄ hydroxyalkyl,C₁ -C₆ alkoxy, C₁ -C₄ alkylthio, phenoxy, C₁ -C₄ haloalkyl, OCF₂ CHF₂,OCF₃, OCHF₂, nitro, cyano, NR₄ R₅, C₃ -C₈ straight or branchedalkenyloxy optionally substituted with one to three halogens, C₃ -C₈straight or branched alkynyloxy optionally substituted with one to threehalogens, or phenyl optionally substituted with one C₁ -C₄ alkyl, C₁ -C₄alkoxy or halogen;

R₃ is hydrogen, halogen, C₁ -C₄ alkyl, C₁ -C₄ alkylthio, C₁ -C₄ alkoxy,CF₃, NO₂, OCF₃, OCHF₂ or OCF₂ CHF₂ ;

R₄ is hydrogen or C₁ -C₄ alkyl;

R₅ is C₁ -C₄ alkyl;

And, when taken together, Y and Z may form a ring in which YZ isrepresented by

(1) the structure: -(CH₂)_(n) -, where n is an integer of 2, 3 or 4; or

(2) by the structure: ##STR2## where, L, M, R₇ and R₈ each representhydrogen, halogen, C₁ -C₄ alkyl or C₁ -C₃ alkoxy, and X is hydrogen;

and when R₁ and R₂ are not the same, the optical isomers thereof andexcept when R is a cation, the acid addition salts thereof. Anembodiment of the invention is compounds of formula II wherein R₁ is CH₃; R₂ is CH(CH₃)₂ ; and X, Y, Z and R₃ each represent hydrogen, halogen,C₁ -C₃ alkoxy or C₁ -C₃ alkyl; or the optical isomers thereof.

As used in the present specification and claims, the term "halogen"means F, Cl, Br or I, unless otherwise specified.

In the present specification and claims, the alkali metals include:sodium, potassium and lithium, although sodium is generally preferred.Also, in the present specification and claims, unless otherwisespecified, the term "organic ammonium" is defined as a group consistingof a positively charged nitrogen atom joined to from one to fouraliphatic groups, each containing from one to 20 carbon atoms. Among theorganic ammonium groups which are illustrative for the preparation ofthe aliphatic ammonium salts of the imidazolidinyl acids are:monoalkylammonium, dialkylammonium, trialklammonium, tetraalkylammonium,monoalkenylammonium, dialkenylammonium trialkenylammonium,monoalkynylammonium, dialkynylammonium, trialkynylammonium,monoalkanolammonium, dialkanolammonium, trialkanolammonium, C₅ -C₆cycloalkylammonium, piperidinium, morpholinium, pyrrolidinium,benzylammonium and equivalents thereof.

Although some 5-oxo-2-imidazolinyl benzoic acids, esters and salts,dihydroimidazoisoindolediones and imidazoisoindolediones arerespectively described as herbicidal agents in U.S. Pat. No. 4,188,487,issued Feb. 20, 1980, U.S. Pat. No. 4,041,045, issued Aug. 9, 1977 andU.S. Pat. No. 4,017,510, issued Apr. 12, 1977; said patents do notteach, suggest or disclose, the substituted or unsubstituted5-thioxo-2-imidazolinyl benzoic acids, esters and salts, the2-thio-dihydroimidazoisoimidolediones or the 2 or 3thio-imidazoisoindolediones of the present invention. It was thereforesurprising to find that the compounds of the present invention, as shownand described above, are highly effective, selective, herbicidal agents,remarkably effective for the control of quackgrass, in the presence ofgraminaceous crops such as rice, barley, wheat, corn, turf, and thelike.

In accordance with the present invention, formula I substituted andunsubstituted 5-thioxo-2-(2-imdazolin-2-yl)benzoic acids, esters andsalts represented by the structure: ##STR3## where R, R₁, R₂, R₃, W, X,Y and Z are as described above, can be prepared by reaction of a formulaXVII substituted or unsubstituted phthalic acid with acetic anhydride,dimethoxyethane and pyridine to give the corresponding phthalicanhydride. The thus-prepared phthalic anhydride of formula XVIII is thenadmixed with an equivalent amount of a formula XXVI thiocarboxamide, inthe presence of an inert organic solvent such as a low-boiling ether(diethyl ether, tetrahydrofuran, dimethoxyethane) acetonitrile, ethylacetate or a halogenated hydrocarbon, at a temperature between 20° and60° C. and preferably 25° to 30° C. under a blanket of inert gas such asnitrogen. When the reaction is essentially complete, the product isisolated by any convenient means, e.g., filtration, distillation of thesolvent or by extraction into aqueous base if the solvent is waterimmiscible. The reaction yields the isomeric phthalamicmonoacid/monoamide products, formulas XXVIIa and XXVIIb.

The thus-formed mixture is then heated to about 25° to 100° C., withabout 2 to 10 molar equivalents of aqueous alcoholic sodium or potassiumhydroxide. The reaction is preferably conducted under a blanket of inertgas, such as nitrogen. If the product is insoluble in water, it willprecipitate from the aqueous phase and be recovered by filtration orextraction. If the product is soluble in water, the mixture can beextracted with an organic solvent such as ether, methylene chloride orthe like, and the extract concentrated to provide an isomeric mixture ofthe formula XXVIIIa and XXVIIIb substituted or unsubstituted2-(5-thioxo-2-imidazolin-2-yl)benzoic acids. Advantageously, the formulaXXVIIIa 2-(5-thioxo-2-imidazolin-2-yl)benzoic acid can be dispersed in anon-protic solvent such as tetrahydrofuran and treated with an equimolaramount of dicyclohexylcarbodiimide to yield the corresponding formula IIsubstituted or unsubstituted tricyclic3-thio-imidazo[2,1-a]isoindole-3(2H), 5-dione. This reaction isgenerally conducted at ambient temperature, preferably under a blanketof inert gas such as nitrogen. The thus-formed formula II tricyclic3-thio-imidazoisoindole-3(2H),5-dione may then be ring opened byreaction with an alcohol in the presence of the corresponding alkalimetal alkoxide, thus affording the formula I ester. The alkoxide isconveniently prepared by reaction of the alcohol with an alkali metal orits hydride. The alcohol may be illustrated by the formula ROH, whereinR is

C₁ -C₁₂ alkyl optionally substituted with one of the following groups:C₁ -C₄ alkoxy, halogen, hydroxyl, C₃ -C₆ cycloalkyl, benzyloxy, furyl,phenyl, halophenyl, C₁ -C₄ alkylphenyl, C₁ -C₄ alkoxyphenyl nitrophenyl,carboxyl, C₁ -C₃ alkoxycarbonyl, cyano or tri(C₁ -C₃)alkylammonium;

C₃ -C₁₂ alkenyl optionally substituted with one of the following groups:C₁ -C₃ alkoxy, phenyl, halogen, or C₁ -C₃ alkoxycarbonyl or with two C₁-C₄ alkoxy groups or two halogen atoms;

C₃ -C₆ cycloalkyl optionally substituted with one or two C₁ -C₃ alkylgroups; or

C₃ -C₁₀ alkynyl.

The formula II dione can also be rearranged to the corresponding formulaIII 2-thio-5H-imidazo[2,1-a]-isoindole-2(3H),5-dione by heating the sameas a solution of acetic acid. A preferred method for the synthesis ofthe formula III 2-thio-5H-imidazo[2,1-a]-isoindole-2-(3H),5-dioneconsists of treating the corresponding benzoic acid of formula I with aslight excess of trifluoroacetic anhydride in a solvent such as THF, orthe like at low temperature, preferably between -60° C. and -50° C. Thethus-formed formula III 2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-dionecan then be reduced with sodium borohydride in ethanol or aqueousethanol to give the formula IV1,9b-dihydro-2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-dione in which Ais hydrogen as a mixture of isomers. Nucleophiles other than hydride ionsuch as water, alcohols, primary and secondary amines and mercaptans canbe added to the >C═N- of Formula III dione to give formula IV diones inwhich

A is hydrogen, hydroxyl, C₃ -C₆ alkenyloxy, C₃ -C₆ alkynyloxy, C₁ -C₆alkylthio, NR₁₃ R₁₄ or C₁ -C₆ alkoxy optionally substituted with phenyl,halophenyl, C₁ -C₃ alkylphenyl, C₁ -C₃ alkoxyphenyl or di-C₁ -C₃alkylaminophenyl;

R₁₃ is hydrogen, C₁ -C₄ alkyl optionally substituted with phenyl,halophenyl, C₁ -C₃ alkylphenyl or C₁ -C₃ alkoxyphenyl;

R₁₄ is hydrogen or C₁ -C₄ alkyl;

The above reactions are graphically illustrated in Flow Diagram I below.##STR4## wherein M is Na or K; R is as described immediately above inreference to useful alcohols and A, X, Y, Z, R₁, R₂ and R₃ are asdescribed above.

From the above discussion, it can be seen that the described syntheticroute to 5-thioxo-2-(2-imidazolinyl)benzoic acids yields isomericmixtures of the herbicidally effective acids. While these isomericmixtures have been found to be very effective for the selective controlof undesirable plant species, it has also been determined that, notinfrequently, one of the isomers is somewhat more effective and/orselective than the other. Thus, it is sometimes desirable to direct asynthesis to a single isomer.

Another method for preparing mono-substituted and multi-substitutedthioxo-2-(2-imidazolinyl)benzoic acids and esters of the presentinvention, involves the reaction of a formula XV, substituted benzoicacid with thionyl chloride and a catalytic amount of dimethylformamideto give the formula XXXIV substituted benzoyl chloride. The reactionmixture is preferably heated to between 25° and 40° C. and thenevaporated in vacuo with an anhydrous aromatic solvent such as toluene,to give the substituted benzoyl chloride. The thus obtained substitutedbenzoyl chloride is then admixed with equimolar amounts of a formulaXXVI thiocarboxamide and a trialkylamine, such as triethylamine,triisopropylamine or the like, in the presence of an non-protic solventsuch as tetrahydrofuran. During the addition of the reactants, thereaction mixture is generally maintained at a temperature between about0° and 15° C. When addition is complete, the mixture is allowed to warmto ambient temperature, then treated with water and extracted with anorganic solvent such as ethyl acetate to obtain the N-substitutedbenzamide of formula XXXV. The thus-formed N-substituted benzamide isthen heated to a temperature of from 25° to 110° C. with about 2 to 10molar equivalents of aqueous or aqueous alcoholic sodium or potassiumhydroxide, preferably under a blanket of inert gas such as nitrogen. Thereaction yields the formula XXXVI substituted phenyl imidazolinethione,which can be converted to the corresponding substituted(5-thioxo-2-imidazolin-2-yl) benzoic acid depicted by formula XXXVII,using secbutyl lithium and carbon dioxide. This reaction is preferablycarried out by dissolving or dispersing the formula XXXVI substitutedphenyl imidazolinthione in tetrahydrofuran or other non-protic solventand about three equivalents of tetramethylenediamine under a blanket ofinert gas such as nitrogen. The reaction mixture is maintained at atemperature between about -70° and -50° C. and then treated with asolution of sec-butyl lithium in cyclohexane. Thereafter, the reactionmixture is admixed with tetrahydrofuran saturated with carbon dioxide toyield the formula XXXVII substituted (5-thioxo-2-imidazolin-2-yl)benzoicacid. These reactions are illustrated graphically in Flow Diagram IIbelow. ##STR5##

Alternatively, the formula XV substituted benzoic acid may be convertedto the formula XXXIV benzoyl chloride, as described above. Thereafter,the benzoyl chloride is dispersed in tetrahydrofuran and admixed with asolution of 3 to 5 and preferably about 4 equivalents of diethylamine intetrahydrofuran. Addition is generally conducted under a blanket ofnitrogen while maintaining the temperature of the reaction mixturebetween about -10° and 0° C. The reaction yields the formula XXXVIIsubstituted benzamide. The above-said substituted benzamide may then bedissolved in anhydrous tetrahydrofuran and treated with an equivalentamount of sec-butyl lithium dispersed in cyclohexane. This treatment isgenerally conducted under a blanket of nitrogen, while maintaining thetemperature of the reaction mixture between about -70° and -50° C.Thereafter, the reaction mixture is admixed with anhydroustetrahydrofuran saturated with carbon dioxide to yield the formula XXXIXsubstituted phthalamic acid. Treatment of a stirred solution of thesubstituted phthalamic acid in dry tetrahydrofuran with ethylchloroformate followed by triethylamine and a solution of a formula XXVIthiocarboxamide in anhydrous tetrahydrofuran, yields the substitutedN,N-diethylphthalamide of formula XL. Base cyclization of the formula XLsubstituted N,N-diethylphthalamide can be achieved by heating saidformula XL compound with from 2 to 10 molar equivalents of aqueous oraqueous alcoholic sodium or potassium hydroxide to a temperature betweenabout 25° and 110° C., preferably under a blanket of nitrogen. Thisreaction yields the formula XLI substitutedN,N-diethyl(5-thioxo-2-imidazolin-2-yl)benzamide, which is readilyconverted to the corresponding acid of formula XLIII by heating with aconcentrated mineral acid such as concentrated hydrochloric orhydrobromic acid. After acidification, the mixture is cooled, basifiedto a pH between 7 and 10, with alkali metal hydroxide, such as sodiumhydroxide or potassium hydroxide and then carefully acified to pH 3 withconcentrated sulfuric acid. The formula XLI substitutedN,N-diethyl(5-thioxo-2-imidazolin-2-yl)benzamide salt also undergoestransesterification with methanol and hydrogen chloride, yielding thecorresponding formula XLII methyl ester of the said formula XLIN,N-diethylbenzamide. Treatment of the formula XLII substituted methyl(5-thioxo-2-imidazolin-2-yl)benzoate with aqueous or aqueous alcoholicalkali metal hydroxide at an elevated temperature between about 60° and100° C., followed by acidification with hydrochloric acid then yieldsthe formula XLIII substituted (5-thioxo-2-imidazolin-2-yl)-benzoic acid.These reactions are illustrated in Flow Diagram III below. ##STR6##

An alternative process for the preparation of substituted2-(5-thioxo-2-imidazolin-2-yl)benzoic acids, involves the reaction of asubstituted benzoyl chloride with a formula XXVI thiocarboxamide in thepresence of a trialkylamine and a solvent such as tetrahydrofuran, toobtain an N-substituted benzamide. This N-substituted amide is thenheated to 25° to 110° C. with an excess of aqueous or aqueous alcoholsodium or potassium hydroxide to yield a formula XLIV substituted phenylimidazolinethione. These reactions are similar to the initial reactionsdescribed above and illustrated in Flow Diagram IV. However, where it isdesirable to provide an additional C₁ -C₃ alkyl substituent on thesubstituted ring of the above-mentioned formula XLIV, imidazolinethione,said imidazolinethione may be dissolved in anhydrous tetrahydrofuran andtreated with sec-butyl lithium, preferably dissolved in cyclohexane orother aromatic solvent. The addition of the sec-butyl lithium to theimidazolinethione is preferably conducted over an extended period oftime, up to several hours, while maintaining the reaction mixture at atemperature between about -50° and -75° C. When addition is complete,the reaction mixture is permitted to warm to between about -30° and -50°C. and then admixed with a C₁ -C₃ alkyl iodide dispersed intetrahydrofuran. After stirring the reaction mixture is allowed to warmto ambient temperature and then the solvent is evaporated in vacuo toobtain the formula XLV multi-substituted product. Reaction isgraphically illustrated in Flow Diagram IV, using methyl iodide andsec-butyl lithium for illustration.

Where it is desirable to provide a halogen substituent on the aromaticring of the formula XLIV substituted imidazolinethione, said substitutedimidazolinethione is dissolved in an anhydrous non-protic solvent suchas tetrahydrofuran and treated with sec-butyl lithium dissolved incyclohexane. The addition is made over a period of from about 0.5 to 2.0hours while maintaining the reaction mixture at a temperature belowabout -50° C. The mixture is then warmed to a temperature between about-30° and -40° C. and halogenated with a halogenating agent such ashexachloroethane or the like, preferably dispersed in an anhydrousnon-protic solvent such as tetrahydrofuran. The mixture is thenpermitted to warm to ambient temperature treated with iced saturatedbrine and then acidified to pH 3 with a strong mineral acid. Thereafter,the formula XLVI halogenated product is extracted from the reactionmixture with an organic solvent such as ether. This formula XLVIhalogenated imidazolinethione is then readily converted to thecorresponding formula XLVII, substituted2-(5-thioxo-2-imidazolin-2-yl)benzoic acid by reaction of saidhalogenated imidazolinethione with sec-butyl lithium in the presence oftetrahydrofuran and tetramethylenediamine under a blanket of nitrogen,followed by admixture of the thus-prepared reaction mixture withanhydrous tetrahydrofuran, saturated with carbon dioxide. The formulaXLVII product may be recovered from the reaction mixture by dispersingsaid mixture in water and acidifying the same with a strong mineralacid. The organic phase is then separated from the mixture and extractedwith base. The aqueous phase is separated and acidified with mineralacid to yield the desired product. These reactions are illustrated inFlow Diagram IV below. ##STR7##

Another alternate route to the preparation of substituted(5-thioxo-2-imidazolin-2-yl)benzoic acids, esters and salts isgraphically illustrated in Flow Diagram VI below. From this flow sheet,it can be seen that a substituted benzoyl chloride is treated with about3 to 5 equivalents of a di-C₁ -C₃ alkylamine, such as diethylamine intetrahydrofuran to yield the corresponding substituted benzamide. Thissubstituted benzamide may then be halogenated, if desired, aftertreatment thereof with sec-butyl lithium in the presence oftetrahydrofuran or other similar solvent. The sec-butyl lithium isgenerally dissolved in cyclohexane and added to the benzamide containingreaction mixture while maintaining the temperature thereof below -50°C., e.g. -50° to -75° C. When addition is complete, the mixture iswarmed to -30° to -40° C. and a halogenating agent, such ashexachloroethane, dispersed in a non-protic solvent added thereto. Thisyields the halogenated derivative of the substituted benzamide which isreadily converted to the corresponding substituted phthalamic acid byreaction with sec-butyl lithium in tetrahydrofuran andtetramethylenediamine under a blanket of nitrogen, followed by admixtureof the thus-prepared composition with tetrahydrofuran saturated withcarbon dioxide. Reaction of the thus-formed substituted phthalamic acid,with ethyl chloroformate followed by triethylamine and a solution of aformula XXVI thiocarboxamide in anhydrous tetrahydrofuran, yields thesubstituted N,N-diethylphthalamide which undergoes base cyclization whenheated to 25° to 110° C., with aqueous or aqueous alcoholic sodium orpotassium hydroxide.

The reaction provides a substitutedN,N-dialkyl-(5-thioxo-2-imidazolin-2-yl)benzamide which is readilyconverted to the corresponding acid by treatment with strong mineralacid or to the corresponding ester by transesterification with a C₁ -C₃alcohol, such as methanol and a strong mineral acid, as shown in FlowDiagram VI. The thus-prepared ester may then be heated with an alkalimetal hydroxide and acidified with strong mineral acid to provide thesubstituted (5-thioxo-2-imidazolin-2-yl)benzoic acid. These reactionsare illustrated in Flow Diagram V below, where it can be seen that thefinal steps of this synthesis route are similar to the latter stages ofthe preparations illustrated in Flow Diagram III, although the earlystages of the systems differ. It should also be noted that this reactionsequence results in the formation of an isomer of the compound preparedby Flow Diagram IV. ##STR8## While herbicidal selectivity of thesubstituted and unsubstituted 5-thioxo-2-imidazolinyl benzoic acids,esters and salts, the thioimidazoisoindolediones, and thedihydrothioimidazoisoindolediones of this invention may vary withcompound structure from crop to crop, the compounds of the invention allappear to show some selectivity in graminaceous crops, particularly ofthe small grain variety, such as rice, barley, wheat, oats or rye. Thisselection thus permits application of the active compounds to newlyplanted fields or to maturing crops for control of undesirable grassesand broadleaf weeds in the presence of said crops.

It is also surprising to find that the compounds of this inventionfrequently exhibit beneficial plant growth regulating (PGR) activitywhen employed at non-herbicidal rates of application. Effective PGRrates will of course, vary from compound to compound and crop to crop,depending on the time of application, weather and soil conditions,foliage density or the like.

When applied to cereal crops such as rice, wheat and barley, it is notuncommon to find that the treated plants are less suseptible to lodgingdue to adverse weather conditions, show increased tillering andfrequently demonstrate increased crop yield.

In practice, the substituted or unsubstituted 5-thioxo-2-imidazolinylbenzoic acids, esters and salts, the thioimidazoisoindolediones, and thedihydrothioimidazoisoindolediones, may be applied to the foliage ofundesirable monocotyledonous or dicotyledonous plants or to soilcontaining seeds or other propagating organs of said plants such astubers, rhizomes or stolons, at ranges generally between about 0.032 and4.0 kg/ha, and preferably between about 0.063 and 2.0 kg/ha, to controlsaid undesirable plant species. These compounds may also be applied atrates as high as 8.0 kg/ha if desired.

In practice, the active compounds of the present invention may beapplied to the foliage of plants or to soil containing seeds or otherpropagating organs thereof, in the form of a liquid spray, as a ULVconcentrate or as a solid formulation.

When the above-said compounds are prepared as alkali metal ororganoammonium salts, said salts are frequently found to be watersoluble and can simply be dispersed in water, with or without theaddition of a surfactant, and applied as an aqueous spray. Saidcompounds may also be prepared as wettable powders, flowableconcentrates, emulsifiable concentrates, granular formulations or thelike.

A typical emulsifiable concentrate can be prepared by dissolving about 5to 25% by weight of the active ingredient in about 65 to 90% by weightof N-methylpyrrolidone, isophorone, butyl cellosolve, methylacetate orthe like and dispersing therein about 5 to 10% by weight of a nonionicsurfactant such as an alkylphenoxy polyethoxy alcohol. This concentrateis dispersed in water for application as a liquid spray or it may beapplied directly as an ultra low volume (ULV) concentrate in the form ofdiscrete droplets having a mass median diameter between about 17 and 150microns particle size.

Wettable powders can be prepared by grinding together about 20 to 45% byweight of a finely divided carrier such as kaolin, bentonite,diatomaceous earth, attapulgite, or the like, 45 to 80% by weight of theactive compound, 2 to 5% by weight of a dispersing agent such as sodiumlignosulfonate, and 2 to 5% by weight of a nonionic surfactant, such asoctylphenoxy polyethoxy ethanol, nonylphenoxy polyethoxy ethanol or thelike.

A typical flowable liquid can be prepared by admixing about 40% byweight of the active ingredient with about 2% by weight of a gellingagent such as bentonite, 3% by weight of a dispersing agent such assodium lignosulfonate, 1% by weight of polyethylene glycol and 54% byweight of water.

When the compounds of the invention are to be used as herbicides wheresoil treatments are involved, the compounds may be prepared and appliedas granular products. Preparation of the granular product can beachieved by dissolving the active compound in a solvent such asmethylene chloride, N-methylpyrrolidone or the like and spraying thethus-prepared solution on a granular carrier such as corncob grits,sand, attapulgite, kaolin or the like.

The granular product thus-prepared generally comprises about 3 to 20% byweight of the active ingredient and about 97 to 80% by weight of thegranular carrier.

In order to facilitate a further understanding of the invention, thefollowing examples are presented primarily for the purpose ofillustrating certain more specific details thereof. The invention is notto be deemed limited thereby except as defined in the claims. Unlessotherwise noted, all parts are by weight.

EXAMPLE 1 Preparation ofN-[1,2-dimethyl-1-(thiocarbamoyl)propyl]-m-toluamide ##STR9##

To a stirred solution containing 5 g 2-amino-2,3-dimethylthiobutylamideand 9.53 mL triethylamine in 50 mL dry THF at -68° C. under nitrogen isadded dropwise 4.52 mL m-toluoyl chloride. After stirring at -68° to-50° C. for one hour, the mixture is allowed to stir at room temperatureovernight. The mixture is poured in 200 mL ice water and the productextracted into methylene chloride. The extract is washed with brine,dried and concentrated to give a yellow oil. Chromatography of this oilor silica gel using 80% hexane-ethyl acetate as eluant gives ananalytically pure sample ofN-[1,2-dimethyl-1-(thiocarbamoyl)propyl]-m-toluamide, mp 108°-110° C.

EXAMPLE 2 Preparation of4-isopropyl-4-methyl-2-m-tolyl-2-imidazolin-5-thione ##STR10##

A solution containing 4.7 gN-[1,2-dimethyl-1-(thiocarbamoyl)propyl]-m-toluamide in 75 mL THF and 35mL 10% NaOH is heated at 65° C. for 18 hours. The THF is removed invacuo and the pH of the cooled residue adjusted to 3 with concentratedH₂ SO₄. The product is extracted into CH₂ Cl₂, the extract washed withbrine, dried and concentrated to give a yellow solid. This isrecrystallized from acetonitrile to give analytically pure4-isopropyl-4-methyl-2-m-tolyl-2-imidazolin-5-thione, mp 122°-123° C.

EXAMPLE 3 Preparation of2-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-p-toluic acid##STR11##

A stirred solution of 1.57 g4-isopropyl-4-methyl-2-m-tolyl-2-imidazolin-5-thione in 15 mL THFcontaining 2.1 mL tetramethylenediamine under nitrogen is cooled to -68°C. and 16.4 mL of a 0.85 mL solution of butyl lithium in hexane addeddropwise. The mixture is stirred at -60° to -40° C. for two hours and 30minutes after which is added to 50 mL THF saturated with CO₂ at -60° C.Stirring is continued overnight at room temperature. The solution ispoured into 100 mL ice water, the pH adjusted to 3 with concentrated H₂SO₄, and extracted with ethyl acetate. The extract is concentrated togive 0.85 g yellow crystalline solid.

This solid is dissolved in 15 mL ethyl acetate which is extracted with15 mL 0.5 N NaOH. The aqueous phase is separated, acidified to pH 3 withconcentrated H₂ SO₄ and the resulting solid removed by filtration,washed and dried to give2-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-p-toluic acid, mp163°-170° C. (dec).

EXAMPLE 4 Preparation of3-fluoro-2-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoic acid##STR12##

To a solution containing 5.47 g 3-fluorophthalic anhydride in 200 mLacetonitrile is added 4.82 g 2-amino-2,3-dimethylthiobutyramide and themixture heated under reflux for 16 hours. The mixture is cooled to 5° C.and the solids removed by filtration. This solid is a mixture of the twointermediate amides.

A solution containing 8.0 g amide in 67 mL 5% NaOH solution is heated at80° C. for two hours and 30 minutes. After cooling, the solution to 5°C., it is acidified with concentrated H₂ SO₄ and the resultingprecipitate extracted into ethyl acetate. The organic phase isseparated, dried and concentrated to give a 7.4 g bright yellow solid,mp 202°-212° C. (dec). The solid is boiled in 125 mL ether, theremaining pale yellow solid removed by filtration and dried. This isanalytically pure3-fluoro-2-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoicacid, mp 220°-222° C. (dec).

EXAMPLE 5 Preparation ofo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoic acid##STR13##

A mixture of 5.92 g (0.04 mol) phthalic anhydride and 5.85 g (0.04 mol)2-amino-2,3-dimethylthiobutyramide in 200 mL methylene chloride isheated under reflux for 16 hours. The cooled solution is extracted with100 mL 2N NaOH and the aqueous extract heated at 80° C. for three hours.The solution is cooled, acidified with concentrated sulfuric acid andfiltered to remove the precipitate which is dried in vacuo to give 11.1g of a mixture of phthalic acid and the desired product.

The solid is boiled in 300 mL acetonitrile, the mixture filtered and thefiltrate cooled to give the desired product as pale yellow crystals, mp192°-198° C. More material can be isolated in the filtrate.Recrystallization of a sample from acetonitrile gives analytically pureo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoic acid, mp204°-206° C. as fine yellow crystals.

EXAMPLE 6 Preparation of2-isopropyl-2-methyl-3-thio-5H-imidazo-[2,1-a]isoindole-3(2H),5-dione##STR14##

To a stirred solution containing 13 g ofo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-benzoic acid in 350mL dry tetrahydrofuran under nitrogen is added 9.71 gdicyclohexylcarbodiimide. After stirring overnight at room temperature,the mixture is filtered and the filtrate concentrated under reducedpressure to give a yellow solid. A sample is chromatographed on silicagel in 5% CH₃ CN-CH₂ Cl₂ to give an analytically pure sample of2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]isoindole-3(2H),5-dione, mp139°-141° C.

Utilizing the above procedure, but substituting the appropriate acid foro-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoic acid, thereare obtained the following compounds.

    ______________________________________                                         ##STR15##                                                                    X        Y         Z         R.sub.3                                                                           mp °C.                                ______________________________________                                        H        H         H         H   136.0-138.0                                                                    .sub.--R-isomer                             A        H         CH.sub.3  H   143.0-150.0                                  H        CH.sub.3  H         H   139.0-140.0                                  H        H         H         F   109.0-112.0                                  H        OCH.sub.3 H         H   172.0-174.0                                  CH.sub.3 H         CH.sub.3  H   132.0-133.0                                  H        (CH.sub.2).sub.2                                                                              H     178.0-180.0                                    H        SCH.sub.3 H         H   180.0-184.0                                  H        CH.sub.2 F                                                                              H         H                                                H        H         CH.sub.2 F                                                                              H                                                ______________________________________                                    

EXAMPLE 7 Preparation of methylo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoate ##STR16##

To a stirred solution containing 47 g2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]isoindole-3(2H),-5-dione in1680 mL methanol under nitrogen is added 850 mg sodium hydride. Themixture is stirred at room temperature overnight. The mixture isconcentrated in vacuo and the residue crystallized from methanol to givemethyl o-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoate mp134°-138° C.

EXAMPLE 8 Preparation of methylo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)benzoatehydrochloride ##STR17##

To a stirred solution containing 3 g methylo-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-benzoate in 120 mLether is added 0.867 mL concentrated HCl. After two hours, theprecipitate was removed by filtration and dried under vacuum at 50° C.overnight. This material is analytically pure and has mp 195°-198° C.(dec).

EXAMPLE 9 Preparation of3-isopropyl-3-methyl-2-thio-5H-imidazo-[2,1-a]isoindole-2(3H),5-dione##STR18##

A solution containing 1 g2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]isoindole-3(2H),5-dione in10 mL glacial acetic acid is heated under reflux for two hours and 30minutes. The solvent is then removed in vacuo, toluene added to theresidue and then removed in vacuo. The residue is chromatographed onsilia gel and the 2,5-dione eluted first using hexane and mixtures ofhexane and ethyl acetate. The analytically pure 2,5-dione had mp152°-158° C.

EXAMPLE 9-A Preparation of3-isopropyl-7-methoxy-3-methyl-2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-dione##STR19##

To a stirred solution containing 1.3 g acid in 150 mL dry THF at -65° C.is added during two hours a solution containing 2.4 mL trifluoroaceticanhydride in 100 mL dry THF. After a further 0.5 hours at -65° C., thesolution is concentrated in vacuo, the residue dissolved in toluene andwashed with water. The organic phase is dried and concentrated. Thereddish solid solid is washed with pentane and dried to giveanalytically pure product mp 159°-161° C.

Using essentially the same procedure but substituting the appropriate3,5-dione for2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]isoindole-3(2H),5-dione inthe above reaction yields the following substituted2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-diones.

    ______________________________________                                         ##STR20##                                                                    X     Y       Z       R.sub.3                                                                             R.sub.1                                                                            R.sub.2 mp °C.                        ______________________________________                                        H     CH.sub.3                                                                              H       H     CH.sub.3                                                                           CH(CH.sub.3).sub.2                           H     H       CH.sub.3                                                                              H     CH.sub.3                                                                           CH(CH.sub.3).sub.2                           H     H       H       H     CH.sub.3                                                                           C.sub.2 H.sub.5                              H     H       H       H     CH.sub.3                                                                           CH.sub.3                                     H     H       H       H     CH.sub.3                                                                           Δ                                      H     H       H       F     CH.sub.3                                                                           CH(CH.sub.3).sub.2                           H     H       H       OCH.sub.3                                                                           CH.sub.3                                                                           CH(CH.sub.3).sub.2                           CH.sub.3                                                                            H       H       CH.sub.3                                                                            CH.sub.3                                                                           CH(CH.sub.3).sub.2                           H     H       H       CH.sub.3                                                                            CH.sub.3                                                                           CH(CH.sub.3).sub.2                           CH.sub.3                                                                            H       CH.sub.3                                                                              H     CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    138.0-140.0                          H     (CH.sub.2).sub. 2                                                                         H       CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    183.0-184.0                            H     SCH.sub.3                                                                             H       H     CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    157.0-159.0                          ______________________________________                                    

EXAMPLE 10 Preparation of 1,7,8,9bα andβ-tetrahydro-3α-isopropyl-3-methyl-2-thio-5H-cyclobut[f]imidazo[2,1-a]isoindole-2(3H),5-dione##STR21##

To a stirred solution containing 0.26 g sodium borohydride in 50 mLabsolute ethanol at -5° C. and under nitrogen is added dropwise 1.6 gdione in 50 mL THF. After stirring 16 hours at room temperature, themixture is concentrated, the residue dissolved in 20 mL water and the pHadjusted to 1 with 6N HCl. The pH is then adjusted again to 4 with 10%NaOH and extracted with ethyl acetate. The combined extracts are washedwith saturated sodium bicarbonate solution followed by brine, dried andconcentrated to give a solid which is crystallized twice from CH₂ Cl₂ togive the cis-product, mp 252°-258° C. The mother liquors are combinedand filtered through a column of neutral alumina. Concentration of theeluent gives the pure trans-isomer, mp 212°-219° C.

Using essentially the same procedure as described above but substitutingthe appropriate imidazo-[2,1-a]isoindole-2-(3H),5-dione for7,8-dihydro-2-isopropyl-2-methyl-3-thio-5H-cyclobut[f]imidazo[2,1-a]-isoindole-3(2H),5-dione,there is obtained the corresponding dihydro derivatives. ##STR22##

    ______________________________________                                                                             cis/                                     R.sub.1                                                                            R.sub.2   X     Y     Z     R.sub.3                                                                           trans mp °C.                      ______________________________________                                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     OCH.sub.3                                                                           H   trans 231.0-234.0                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     OCH.sub.3                                                                           H   cis   198.0-201.0                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     H     F   trans 235.0-242.0                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     H     H   trans 195.0-196.0                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     H     H   cis   232.0-233.0                        CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     SCH.sub.3                                                                           H     H   trans                                    CH.sub.3                                                                           C.sub.2 H.sub.5                                                                         H     H     H     H   cis                                      CH.sub.3                                                                           C.sub.2 H.sub.5                                                                         H     H     H     H   trans/                                                                        cis                                      CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                      H     H     CH.sub.3                                                                            H   trans/                                                                        cis                                      CH.sub.3                                                                           Δ   H     H     H     H   trans/                                                                        cis                                      ______________________________________                                    

EXAMPLE 10-A Preparation of1,9b-dihydro-3α-isopropyl-9bα-methoxy-3-methyl-2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-dione##STR23##

A solution containing 1 g freshly prepared dione is dissolved in 50 mLanhydrous methanol. After standing at room temperature for one hour, themixture is concentrated and the residue recrystallized from acetonitrileto give analytically pure product, mp 158°-161° C.

Using essentially the same procedure but substituting the appropriatenucleophile for methanol, in an appropriate solvent such as THF,acetonitrile, and the appropriate dione for3-isopropyl-3-methyl-2-thio-5H-imidazo[2,1-a]isoindole-2(3H),5-dione,the following are obtained.

    ______________________________________                                         ##STR24##                                                                    X       Y         Z         R.sub.3 A                                         ______________________________________                                        H       H         OCH.sub.3 H       OCH.sub.3                                 H       H         H         H       NH.sub.2                                  H       H         H         H       SCH.sub.3                                 H       H         H         H       OH                                        H       H         H         H       NHCH.sub.3                                H       (CH.sub.2).sub.2                                                                              H         OCH.sub.3                                   CH.sub.3                                                                              H         CH.sub.3  H       OCH.sub.3                                 H       H         H         CH.sub.2 F                                                                            OCH.sub.3                                 H       SCH.sub.3 H         H       OCH.sub.3                                 H       H         H         H       OPr -n                                    ______________________________________                                    

EXAMPLE 11 Preparation ofN-(1-carbamoyl-1,2-dimethylpropyl)-p-thiotoluamide ##STR25##

A stirred mixture containing 13.0 g (0.10 mol) of2-amino-2,3-dimethylbutyramide and 15.3 mL (0.11 mol) of triethylaminein 150 mL of dry THF is treated drop-wise at -70° C. with a solution of15.5 g (0.10 mol) of p-toluoyl chloride in 25 mL dry THF. After beingallowed to warm to ambient temperatures over a 16 hour period, thereaction mixture is treated with 50 mL water and stirred for one hour.The resulting three phases are filtered; the filtrate is separated andthe aqueous phase is extracted with 150 mL ethyl acetate. All organicphases are combined, washed with 100 mL of a saturated NaCl solution,dried over magnesium sulfate and concentrated in vacuo. A yellow solidresidue is obtained. The nmr spectrum is consistent with the desiredstructure. This is purified by chromatography on silica gel usinghexanes:ethyl acetate (70:30) as solvent. This yields the pure productmp 156°-157° C.

EXAMPLE 12 Preparation of4-isopropyl-4-methyl-2-p-tolyl-2-imidazolin-5-thione ##STR26##

A mixture of 24.8 g (0.10 mol) ofN-(1-carbamoyl-1,2-dimethylpropyl)-p-toluamide in 263 mL of a 2.5Nsodium hydroxide solution (0.50 mol NaOH) is heated with 100 mLp-dioxane and heated on a steam bath for 16 hours. The p-dioxane isremoved in vacuo and the remaining aqueous solution is cooled to 5°-10°C. After carefully acidifying to pH 3-4 with concentrated sulfuric acid,the reaction mixture is extracted with a total of 750 mL methylenechloride. The organic phase is washed with 200 mL of a saturated sodiumchloride solution, dried over magnesium sulfate and evaporated todryness in vacuo to give a yellow solid residue. The nmr spectrum isconsistent with the desired structure. This compound can berecrystallized from acetonitrile to give analytically pure4-isopropyl-4-methyl-2-p-tolyl-2-imidazolin-5-thione mp 167°-170° C.

EXAMPLE 13 Preparation of2-(2-chloro-p-tolyl)-4-isopropyl-4-methyl-2-imidazolin-5-thione##STR27##

A mechanically stirred solution of 20.0 g of4-isopropyl-4-methyl-2-p-tolyl-2-imidazolin-5-thione in 200 mL of drytetrahydrofuran is treated dropwise with 160 mL of a 1.2M solution ofsec-butyl lithium (0.191 mol) in cyclohexane over a 40 minute period at-72° to -65° C. After stirring the resulting solution at -40° to -35°for one and one-half hours, a solution of 21.4 g (0.090 mol) ofhexachloroethane in 125 mL of dry tetrahydrofuran is added dropwise.Addition temperature is allowed to reach -20° C. After warming to roomtemperature over a 16 hour period, the reaction is treated with 200 mLof ice water plus 200 mL of a saturated sodium chloride solution. Themixture is carefully acidified to pH 3 with concentrated sulfuric acid.The phases are separated and the aqueous phase is extracted with 200 mLether. The organic phases are combined, dried over magnesium sulfate andconcentrated to an oily residue. The residue is purified bychromatography on silica gel to give pure2-(2-chloro-p-tolyl)-4-isopropyl-4-methyl-2-imidazolin-5-thione.

EXAMPLE 14 Preparation of5-chloro-6-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-m-toluicacid ##STR28##

A stirred solution of 3.7 g of2-(2-chloro-p-tolyl)-4-isopropyl-4-methyl-2-imidazolin-5-thione in 70 mLanhydrous tetrahydrofuran and 4.7 mL (0.031 mol) ofN,N,N',N'-tetramethylethylenediamine under N₂ is treated at -70° to -63°C. dropwise with 26 mL of a 1.2M solution of sec-butyl lithium (0.031mol) in cyclohexane. After stirring for two hours at -55° to -45° C.,the reaction is poured over 300 mL anhydrous THF saturated with carbondioxide. The mixture is allowed to come to room temperature over a 16hour period and then treated with 250 mL water and carefully acidifiedwith ice cooling, to pH 3 with concentrated sulfuric acid. The phasesare separated; the aqueous phase is extracted with 150 mL of ethylacetate. The organic phases are combined and extracted with 50 mL of an0.5N solution of sodium hydroxide. The basic aqueous phase is cooled to5°-10° C. and carefully acidified to pH 3 with concentrated sulfuricacid and the product extracted into methylene chloride. This isrecrystallized to give pure5-chloro-6-(4-isopropyl-4-methyl-5-thioxo-2-imidazolin-2-yl)-m-toluicacid.

EXAMPLE 15 Preparation of acids and esters

The procedures described in the above Examples are effective forpreparing a wide variety of substituted and unsubstituted5-thioxo-2-(2-imidazolin-2-yl)benzoic acids and esters. Among the5-thioxo-2-(2-imidazolin-2-yl)benzoic acids and esters prepared by theprocedures described above are those listed in Table I.

                                      TABLE I                                     __________________________________________________________________________    Compounds prepared by the procedures described in Examples 1-19 having        the structure:                                                                 ##STR29##                                                                    R         R.sub.1                                                                          R.sub.2                                                                             X   Y      Z      R.sub.3                                                                           mp °C.                        __________________________________________________________________________    CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  NO.sub.2                                                                          H      H      (NO.sub.2)                                                                        -- IM*                               H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      F   220-222                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  F   H      H      (F) -- IM                                H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      NO.sub.2                                                                             H   --                                   CH.sub.3  CH.sub.3                                                                         CH(CH.sub. 3).sub.2                                                                 NO.sub.2                                                                          H      H      H   --                                   CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      NO.sub.2                                                                             H   --                                   CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      CH.sub.3                                                                             Cl                                       CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  CH.sub.3                                                                          H      H      CH.sub.3                                 H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  CH.sub.3                                                                          CHCH.sub.2CHCH.sub.2                                                                        H                                        H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  CH.sub.3                                                                          H      CH.sub.3                                                                             Cl                                       H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   204-206                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   134-138                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      F   164-172                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   172-175 ( .sub.--R)                  CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   161-163 ( .sub.--R)                  CH.sub.2 C.sub.6 H.sub.5                                                                CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   142-144                               ##STR30##                                                                              CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H                                         ##STR31##                                                                              CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H                                        CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   CH.sub.3                                                                             H      H   178-181                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      CH.sub.3                                                                             H   163-172                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   CH.sub.3                                                                             (CH.sub.3)                                                                           H   149-160 IM                           H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   CH.sub.3                                                                             (CH.sub.3)                                                                           H   105-123 IM                           CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   CH.sub.3                                                                             H      H   188-191                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   CH.sub.3                                                                             H      H   133-141                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      OCH.sub.3                                CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      OCH.sub.3                                H         CH.sub.3                                                                         C.sub.2 H.sub.5                                                                     H   H      H      H                                        H         CH.sub.3                                                                         CH.sub.3                                                                            H   H      H      H                                        CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   OCF.sub.3                                                                            H      H   158-159                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  SCH.sub.3                                                                         H      H      H   100-104                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  SCH.sub.3                                                                         H      H      H   103-113                              OCH.sub.2 CCH                                                                           CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   148-150                              C.sub.2 H.sub.5                                                                         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   132.5-134                             ##STR32##                                                                              CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   150-152                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   195-198 (dec)                                                                 HCl salt                             CH(CH.sub.3).sub.2                                                                      CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   127-129                              Na.sup.+  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   175-200 (dec)                        Ca.sup.++ /2                                                                            CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      H      H   >285                                 H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   H      C.sub.2 H.sub.5                                                                      H                                        H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   C.sub.2 H.sub.5                                                                      H      H                                        H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  CH.sub.3                                                                          H      CH.sub.3                                                                             H   191-193                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   (CH.sub.2).sub.2                                                                            H   187-192                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  CH.sub.3                                                                          H      CH.sub.3                                                                             H   128-130                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   OCH.sub.3                                                                            H      H   170-171.5                            CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   (CH.sub.2).sub.2                                                                            H   199-201                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   OCH.sub.3                                                                            H      H   124-126                              CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   OCHF.sub.2                                                                           (OCHF.sub.2)                                                                         H   141-146 IM                           CH.sub.3  CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   SCH.sub.3                                                                            H      H   184-187                              H         CH.sub.3                                                                         CH(CH.sub.3).sub.2                                                                  H   SCH.sub.3                                                                            H      H   210-214                              __________________________________________________________________________     *IM  indicates that the product is a mixture of isomers, the second being     shown as ().                                                             

EXAMPLE 16 Postemergence herbicidal evaluation of test compounds

The postemergence herbicidal activity of the compounds of the presentinvention is demonstrated by the following tests, wherein a variety ofmonocotyledonous and dicotyledonous plants are treated with testcompounds dispersed in aqueous acetone mixtures. In the tests, seedlingplants are grown in jiffy flats for about two weeks. The test compoundsare dispersed in 50/50 acetone/water mixtures containing 0.5% TWEEN® 20,a polyoxyethylene sorbitan monolaurate surfactant of Atlas ChemicalIndustries, in sufficient quantities to provide the equivalent of about0.063 to 4.0 kg per hectare of active compound when applied to theplants through a spray nozzle operating at 40 psig for a predeterminedtime. After spraying, the plants are placed on greenhouse benches andare cared for in the usual manner, commensurate with conventionalgreenhouse practices. From four to five weeks after treatment, theseedling plants, are examined and rated according to the rating systemprovided below. The data obtained are recorded in Table II below.

    ______________________________________                                                             % Difference in Growth                                   Rating System        from the Check                                           ______________________________________                                        0 - No Effect            0                                                    1 - Possible effect       1-10                                                2 - Slight effect        11-25                                                3 - Moderate effect      26-40                                                5 - Definite injury      41-60                                                6 - Herbicidal effect    61-75                                                7 - Good herbicidal effect                                                                             76-90                                                8 - Approaching complete kill                                                                          91-99                                                9 - Complete kill        100                                                  4 - Abnormal growth, that is, a definite                                          physiological malformation but                                                with an over-all effect less than a 5                                         on the rating scale.                                                      ______________________________________                                    

In most cases the data are for a single test, but in several instances,they are average values obtained from more than one test.

    ______________________________________                                        Plant Species Used                                                            ______________________________________                                        Barnyardgrass     (Echinochloa crusgalli)                                     Purple Nutsedge   (Cyperus rotundus L.)                                       Wild Oats         (Avena fatua)                                               Quackgrass        (Agropyron repens)                                          Field Bindweed    (Convolvulus arvensis L.)                                   Morningglory      (Ipomoea purpurea)                                          Velvetleaf        (Abutilon theophrasti)                                      Barley            (Hordeum vulgare)                                           Corn              (Zea mays)                                                  Soybean           (Glycine max)                                               Wheat             (Triticum aestivum)                                         ______________________________________                                    

    TABLE II      POST-EMERGENCE TEST - RATES IN KG/HA   BARNY P NUT WILD QUACK FLD B     MRNGL VELVE S BAR CORN SOYBE S WHE Compound RATE ARDGR SEDGE OATS GRASS     INDWD RY SP TLEAF LY LA FIELD AN WI AT ER       -o-(4-Isopropyl-4-methyl- 2.000 9.0 8.0 9.0 8.0 8.0 8.0 8.0 8.0 9.0     8.0  5-thioxo-2-imidazolin- 1.000 90 7.5 9.0 8.0 9.0 8.0 8.5 67.0 8.5     8.0 2-yl)benzoic acid; .500 9.0 6.5 9.0 6.5 7.5 6.5 7.5 5.5 8.5 8.0     .250 5.0 4.5 5.5 7.5 7.5 5.5 4.0 4.5 7.5 7.5  .125 2.5 4.0 3.5 4.0 5.0     4.5 2.5 2.0 6.0 7.0  .063 1.0 2.0 0.5 2.0 2.5 2.5 1.0 1.0 2.5 6.0  .032     0.0 2.0 0.0 0.0 3.0 3.0 0.0 1.0 2.0 5.0 Methyl -o-(4-isopropyl- 2.000     3.0 5.0 9.0 0.0 6.0 8.0 7.0 0.0 6.0 8.0 4-methyl-5-thioxo-2- 1.000 0.0     2.0 5.0 0.0 0.0 4.0 4.0 0.0 6.0 8.0 imidazolin-2-yl)benzoate: .500 0.0     0.0 4.0 0.0 0.0 2.0 3.0 0.0 1.0 7.0  .250 0.0 0.0 0.0 0.0 0.0 1.0 1.0     0.0 0.0 5.0  .125 0.0 0.0 0.0 0.0 0.0 1.0 1.0 0.0 0.0 4.0  .063 0.0 0.0     0.0 0.0 0.0 1.0 1.0 0.0 0.0 3.0 3-Fluoro-2-(4-isopropyl- 2.000 9.0 8.0     4.0  8.0 8.0 9.0 3.0 3.0 8.0 4-methyl-5-thioxo-2- 1.000 7.0 8.0 2.0 0.0     8.0 8.0 7.0 1.0 2.0 8.0 imidazolin-2-yl)benzoic .500 4.0 8.0 2.0  9.0     8.0 7.0 2.0 3.0 8.0 acid; .250 2.0 6.0 0.0 0.0 8.0 8.0 6.0 1.0 2.0 8.0     .125 0.0 3.0 0.0  7.0 7.0 4.0 1.0 2.0 6.0  .063 0.0 3.0 0.0  5.0 6.0 2.0     0.0 1.0 6.0 (R)-(+)--o-(4-Isopropyl- 2.000 9.0 8.0 9.0 8.0 9.0 8.0 9.0     7.0 9.0 8.0 4-methyl-5-thioxo-2- 1.000 9.0 8.0 9.0 8.0 9.0 8.0 9.0 4.0     9.0 8.0 imidazolin-2-yl)benzoic .500 9.0 7.0 9.0 5.0 9.0 8.0 9.0 6.0 9.0     8.0 acid; .250 7.0 7.0 7.0 6.0 9.0 8.0 6.0 2.0 9.0 8.0  .125 5.0 7.0 4.0     4.0 7.0 6.0 3.0 3.0 9.0 7.0  0.63 2.0 3.0 0.0 0.0 5.0 6.0 1.0 1.0 8.0     7.0 (-R)-(+)-Methyl -o-(4- 2.000 8.0 7.0 7.0 0.0 6.0 8.0 8.0 4.0 7.0 8.0     isopropyl-4-methyl-5- 1.000 5.0 7.0 6.0 0.0 5.0 6.0 7.0 1.0 8.0 8.0     thioxo-2-imidazolin- .500 3.0 6.0 4.0 0.0 2.0 4.0 7.0 2.0 8.0 7.0     2-yl)benzoate; .250 1.0 2.0 4.0 0.0 0.0 2.0 4.0 1.0 8.0 7.0  .125 0.0     0.0 2.0 0.0 0.0 0.0 2.0 0.0 7.0 6.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0     0.0 5.0 5.0 Benzyl -o-(4-isopropyl- 2.000 0.0 0.0 0.0 0.0 0.0 7.0 5.0     3.0 2.0 4.0 4-methyl-5-thioxo-2- 1.000 0.0 0.0 0.0 0.0 0.0 6.0 3.0 3.0     1.0 3.0 imidazolin-2-yl)- .500 0.0 0.0 0.0 0.0 0.0 4.0 2.0 2.0 0.0 3.0     benzoate; Isopropylammonium -o-(4- 2.000 9.0 8.0 9.0 8.0 9.0 9.0 9.0 9.0     9.0 8.0 isopropyl-4-methyl-5- 1.000 9.0 8.0 9.0 7.0 9.0 9.0 9.0 7.0 9.0     8.0 thioxo-2-imidazolin-2- .500 7.0 8.0 7.0 6.0 9.0 7.0 9.0 7.0 9.0 8.0     yl)benzoic acid; .250 6.0 6.0 6.0 2.0 6.0 8.0 6.0 5.0 7.0 7.0  .125 2.0     3.0 4.0 0.0 5.0 5.0 4.0 2.0 7.0 5.0  .063 0.0 2.0 3.0 0.0 0.0 4.0 2.0     2.0 6.0 5.0 Benzyltrimethylammonium 2.000 9.0 8.0 9.0 7.0 9.0 8.0 9.0     6.0 9.0 8.0 -o-(4-isopropyl-4-methyl- 1.000 7.0 8.0 8.0 6.0 8.0 8.0 9.0     4.0 9.0 8.0 5-thioxo-2-imidazolin-2- .500 6.0 8.0 6.0 3.0 7.0 6.0 7.0     3.0 9.0 7.0 yl)benzoic acid; .250 3.0 4.0 4.0 0.0 5.0 4.0 5.0 3.0 7.0     7.0  .125 2.0 3.0 0.0 0.0 4.0 2.0 2.0 2.0 7.0 6.0  .063 0.0 2.0 0.0 0.0     3.0 0.0 0.0 2.0 4.0 5.0 2-Propynyl -o-(4-iso- 2.000 8.0 8.0 7.0 6.0 7.0     8.0 8.0 6.0 9.0 8.0 propyl-4-methyl-5-thioxo- 1.000 7.0 6.0 8.0 4.0 8.0     8.0 8.0 5.0 9.0 8.0 2-imidazolin-2-yl)- .500 4.0 6.0 4.0 2.0 9.0 6.0 4.0     3.0 8.0 8.0 benzoate; .250 0.0 3.0 3.0 0.0 6.0 4.0 2.0 2.0 7.0 8.0  .125     0.0 2.0 2.0 0.0 6.0 4.0 0.0 2.0 6.0 6.0  .063 0.0 0.0 0.0 0.0 3.0 2.0     0.0 1.0 5.0 5.0 Ethyl -o-(4-isopropyl-4- 2.000 0.0 8.0 7.0 0.0 0.0 3.0     5.0 2.0 3.0 5.0 methyl-5-thioxo-2-imidaz- 1.000 0.0 6.0 6.0 0.0 0.0 3.0     4.0 1.0 2.0 6.0 olin-2-yl)benzoate; .500 0.0 5.0 5.0 0.0 0.0 2.0 3.0 1.0     2.0 5.0  .250 0.0 2.0 3.0 0.0 0.0 0.0 2.0 0.0 1.0 5.0  .125 0.0 2.0 2.0     0.0 0.0 0.0 0.0 0.0 1.0 5.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     3.0 Furfuryl -o-(4-isopropyl- 2.000 8.0 8.0 6.0 3.0 8.0 8.0 8.0 4.0 9.0     7.0 4-methyl-5-thioxo-2- 1.000 8.0 7.0 6.0 2.0 8.0 7.0 6.0 3.0 7.0 7.0     imidazolin-2-yl)- .500 5.0 7.0 3.0 1.0 8.0 7.0 5.0 3.0 7.0 6.0 benzoate;     .250 2.0 2.0 2.0 0.0 4.0 5.0 3.0 2.0 5.0 5.0  .125 0.0 0.0 0.0 0.0 0.0     0.0 1.0 1.0 2.0 4.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 3.0 Methyl     -o-(4-isopropyl-4- 2.000 5.0 7.0 7.0 0.0 5.0 6.0 6.0 3.0 8.0 7.0         5     methyl---thioxo-2-imidaz- 1.000 2.0 6.0 6.0 0.0 2.0 4.0 4.0 2.0 8.0 7.0     olin-2-yl)benzoate hydro- .500 0.0 6.0 6.0 0.0 1.0 3.0 3.0 2.0 8.0 7.0     chloride; .250 0.0 0.0 3.0 0.0 0.0 2.0 2.0 2.0 4.0 7.0  .125 0.0 0.0 2.0     0.0 0.0 0.0 0.0 0.0 4.0 5.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0     4.0 Methyl 3-fluoro-2- 2.000 0.0 5.0 0.0  8.0 8.0 6.0 0.0 0.0 8.0     (4-isopropyl-4- 1.000 0.0 3.0 0.0  6.0 7.0 3.0 0.0 0.0 8.0 methyl-5-thiox     o-2- .500 0.0 2.0 0.0 0.0 6.0 6.0 2.0 0.0 0.0 8.0 imidazolin-2-yl)- .250     0.0 0.0 0.0 0.0 4.0 5.0 0.0 0.0 0.0 7.0 benzoate. .125 0.0 0.0 0.0 0.0     3.0 3.0 0.0 0.0 0.0 6.0  .063 0.0 0.0 0.0 0.0 2.0 2.0 0.0 0.0 0.0     6.0

EXAMPLE 17 Preemergence herbicidal evaluation of test compounds

The preemergence herbicidal activity of the compounds of the presentinvention is exemplified by the following tests in which the seeds of avariety of monocotyledonous and dicotyledonous plants are separatelymixed with potting soil and planted on top of approximately one inch ofsoil in separate pint cups. After planting, the cups are sprayed withthe selected aqueous acetone solution containing test compound insufficient quantity to provide the equivalent of about 0.063 to 4.0 kgper hectare of test compound per cup. The treated cups are then placedon greenhouse benches, watered and cared for in accordance withconventional greenhouse procedures. From four to five weeks aftertreatment, the tests are terminated and each cup is examined and ratedaccording to the rating system set forth above. The herbicidalproficiency of the active ingredients of the present invention isevident from the test results which are recorded in Table III below.Where more than one test is involved for a given compound, the data areaveraged.

    TABLE III      PRE-EMERGENCE TESTS - RATES IN KG/HA   BARNY P NUT WILD QUACK FLD B     MRNGL VELVE S BAR CORN SOYBE Compound RATE ARDGR SEDGE OATS GRASS INDWD     RY SP TLEAF LY LA FIELD AN WI       -o-(4-Isopropyl-4-methyl- 2.000 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0     8.0 5-thioxo-2-imidazolin- 1.000 9.0 9.0 8.5 9.0 9.0 8.0 9.0 7.3 9.0 8.5     2-yl)benzoic acid; .500 7.0 9.0 5.5 9.0 9.0 8.0 8.5 6.0 8.5 8.5  .250     6.5 9.0 3.5 9.0 9.0 8.0 8.0 3.7 7.5 7.5  .125 4.5 9.0 2.0 9.0 9.0 7.5     7.0 2.7 6.5 7.5  .063 1.5 6.3* 1.5 6.3* 8.0 4.5 5.0 1.7 2.0 6.5  .032     3.0 4.5* 0.0 4.5* 4.5* 9.0 9.0 1.0 2.0 7.0 Methyl -o-(4-isopropyl- 2.000     8.0 9.0 8.0 6.5 9.0 8.0 9.0 3.5 5.0 8.0 4-methyl-5-thioxo-2- 1.000 8.0     8.0 8.0 4.5 9.0 8.0 8.0 1.5 4.0 8.0 imidazolin-2-yl)benzoate; .500 6.0     7.0 8.0 2.5 8.5 6.0 7.0 0.0 3.0 8.0  .250 2.0 3.5 7.0 1.0 3.0 5.0 5.0     0.0 2.0 5.0  .125 0.0 2.5 8.0 0.0 3.5* 2.0 4.0 0.0 0.0 4.0  .063 0.0 1.0     3.0 0.0 0.0 0.0 1.0 0.0 0.0 3.0  .032  0.0  0.0 0.0   0.0 3-Fluoro-2-(4-i     sopropyl- 2.000 9.0 9.0 6.0 9.0 9.0 8.0 9.0 5.0 9.0 8.0 4-methyl-5-thioxo     -2- 1.000 7.0 9.0 3.0 9.0 9.0 8.0 8.0 4.0 7.0 7.0 imidazolin-2-yl)benzoic      .500 6.0 9.0 2.0 9.0 9.0 8.0 9.0 2.0 7.0 7.0 acid; .250 6.0 9.0 0.0 9.0     9.0 8.0 8.0 1.0 3.0 5.0  .125 0.0 3.0 0.0 0.0 6.0 7.0 3.0 0.0 1.0 5.0     .063 0.0 0.0 0.0 0.0  4.0 2.0 0.0 0.0 4.0 (R)-(+)--o-(4-Isopropyl- 2.000     9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 8.0 4-methyl-5-thioxo-2- 1.000 9.0     9.0 9.0 9.0 9.0 8.0 9.0 8.0 9.0 8.0 imidazolin-2-yl)benzoic .500 9.0 9.0     9.0 9.0 9.0 8.0 8.0 8.0 9.0 8.0 acid; .250 9.0 9.0 6.0 9.0 9.0 8.0 8.0     5.0 9.0 8.0  .125 6.0 9.0 3.0 9.0 9.0 8.0 9.0 4.0 9.0 8.0  .063 6.0 9.0     2.0 9.0 9.0 8.0 8.0 3.0 7.0 8.0 (-R)-(+)-Methyl -o-(4- 2.000 8.0 9.0 9.0     9.0 9.0 8.0 9.0 5.0 7.0 9.0 isopropyl-4-methyl-5- 1.000 8.0 9.0 9.0 9.0     9.0 8.0 9.0 2.0 8.0 8.0 thioxo-2-imidazolin- .500 7.0 9.0 7.0 9.0 9.0     8.0 8.0 3.0 5.0 8.0 2-yl)benzoate; .250 4.0 7.0 6.0 9.0 9.0 6.0 5.0 1.0     3.0 8.0  .125 3.0 6.0 4.0 9.0 2.0 4.0 3.0 2.0 2.0 9.0  .063 2.0 3.0 2.0     9.0 0.0 3.0 2.0 1.0 2.0 5.0 Benzyl -o-(4-isopropyl- 2.000 4.0 8.0 3.0     9.0 9.0 8.0 7.0 2.0 3.0 5.0 4-methyl-5-thioxo-2- 1.000 0.0 3.0 0.0 9.0     5.0 3.0 3.0 0.0 2.0 3.0 imidazolin-2-yl)- .500 0.0 3.0 0.0 9.0 0.0 2.0     2.0 1.0 2.0 2.0 benzoate; .250 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 1.0 1.0     .125 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 1.0 1.0  .063 0.0 0.0 0.0 0.0 0.0     0.0 0.0 0.0 1.0 1.0 Isopropylammonium -o-(4- 2.000 7.0 9.0 9.0 9.0 9.0     8.0 9.0 9.0 9.0 9.0 isopropyl-4-methyl-5- 1.000 7.0 9.0 8.0 9.0 9.0 8.0     8.0 9.0 9.0 9.0 thioxo-2-imidazolin-2- .500 5.0 9.0 6.0 6.0 9.0 8.0 8.0     6.0 9.0 8.0 yl)benzoic acid; .250 3.0 9.0 3.0  9.0 6.0 8.0 3.0 4.0 7.0     .125 2.0 9.0 3.0 0.0 9.0 4.0 4.0 3.0 3.0 7.0  .063 1.0 5.0 2.0 0.0 9.0     3.0 2.0 2.0 2.0 Benzyltrimethylammonium 2.000 8.0 9.0 9.0 9.0 9.0 8.0     8.0 9.0 8.0 0.0 -o-(4-isopropyl-4-methyl- 1.000 8.0 9.0 5.0 9.0 9.0 8.0     8.0 5.0 7.0 9.0 5-thioxo-2-imidazolin-2- .500 5.0 9.0 4.0 9.0 9.0 8.0     8.0 3.0 6.0 9.0 yl)benzoic acid; .250 3.0 6.0 2.0 9.0 9.0 8.0 6.0 2.0     4.0 5.0  .125 2.0 5.0 2.0 0.0 9.0 9.0 3.0 2.0 3.0  0.63 1.0 2.0 0.0 0.0     5.0 4.0 2.0 1.0 2.0 3.0 2-Propynyl -o-(4-iso- 2.000 9.0 9.0 9.0 9.0 9.0     8.0 9.0 9.0 7.0 8.0 propyl-4-methyl-5-thioxo- 1.000 7.0 9.0 9.0 9.0 9.0     8.0 8.0 5.0 6.0 8.0 2-imidazolin-2-yl)- .500 7.0 9.0 6.0 9.0 9.0 8.0 8.0     4.0 5.0 9.0 benzoate; .250 6.0 9.0 3.0 9.0 9.0 8.0 6.0 3.0 3.0 8.0  .125     0.0 8.0 3.0 9.0 3.0 9.0 4.0 2.0 2.0 8.0  .063 0.0 5.0 2.0 9.0 4.0 2.0     2.0 1.0 2.0 5.0 Ethyl -o-(4-isopropyl-4- 2.000 3.0 8.0 9.0 9.0 0.0 7.0     6.0 3.0 2.0 9.0 methyl-5-thioxo-2-imidaz- 1.000 2.0 8.0 9.0 9.0 0.0 4.0     4.0 2.0 1.0 6.0 olin-2-yl)benzoate; .500 0.0 7.0 8.0 9.0 0.0 2.0 3.0 1.0     2.0  .250 0.0 6.0 6.0 0.0 0.0 0.0 1.0 1.0 1.0 3.0  .125 0.0 6.0 5.0  0.0     0.0 0.0 0.0 2.0 0.0  .063 0.0 3.0 3.0  0.0 0.0 0.0 0.0 0.0 0.0 Furfuryl  o     --(4-isopropyl- 2.000 7.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 8.0 4-methyl-5-     thioxo-2- 1.000 7.0 9.0 8.0 9.0 9.0 8.0 9.0 5.0 9.0 8.0 imidazolin-2-yl)-      .500 7.0 9.0 6.0 9.0 9.0 8.0 9.0 5.0 6.0 benzoate; .250 6.0 9.0 2.0 9.0     9.0 6.0 4.0 2.0 3.0 5.0  .125 2.0 9.0 0.0 9.0 9.0 6.0 5.0 3.0 2.0 4.0     .063 0.0 3.0 0.0 0.0 0.0 3.0 3.0 3.0 2.0 3.0 Methyl -o-(4-isopropyl-4-     2.000 9.0 9.0 9.0 3.0 9.0 8.0 9.0 4.0 7.0 9.0 methyl-5-thioxo-2-imidaz-     1.000 4.0 8.0 8.0  6.0 6.0 8.0 0.0 5.0 8.0 olin-2-yl)benzoate hydro-     .500 4.0 8.0 6.0 0.0 4.0 3.0 5.0 2.0 2.0 7.0 chloride; .250 2.0 4.0 5.0     0.0 0.0 2.0 3.0 0.0 1.0 6.0  .125 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     3.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 Isopropyl  -o-(4-iso-     2.000 0.0 6.0 0.0 9.0 0.0 3.0 3.0 0.0 0.0 3.0 propyl-4-methyl-5- 1.000     0.0 3.0 0.0 9.0 0.0 3.0 2.0 0.0 0.0 2.0 thioxo-2-imidazolin- .500 0.0     3.0 0.0 9.0 0.0 3.0 0.0 0.0 0.0 0.0 2-yl)benzoate; .250 0.0 3.0 0.0 9.0     0.0 0.0 0.0 0.0 0.0 0.0  .125 0.0 2.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0     .063 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0 Methyl 3-fluoro-2- 2.000     7.0 9.0 7.0 9.0 9.0 8.0 8.0 0.0 4.0 8.0 (4-isopropyl-4- 1.000 4.0 7.0     2.0 9.0 9.0 8.0 7.0 0.0 3.0 8.0 methyl-5-thioxo-2- .500 2.0 5.0 0.0 0.0     8.0 7.0 5.0 0.0 0.0 7.0 imidazolin-2-yl)- .250 0.0 3.0 0.0 0.0 8.0 6.0     5.0 0.0 0.0 7.0 benzoate. .125 0.0 0.0 0.0 0.0 2.0 3.0 2.0 0.0 0.0 3.0     .063 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 3.0

EXAMPLE 18 Postemergence herbicidal evaluation of test compounds

The postemergence herbicidal activity of test compounds is determinedusing the procedure of Example 16, excepting that test compounds areapplied at rates of application between 0.063 and 2.0 kg/ha to thefoliage of test plant species. The rating system employed is the same asthat described in Example 16, and the plant species used are as follows:

    ______________________________________                                        Barnyardgrass     (Echinochloa crusgalli)                                     Purple Nutsedge   (Cyperus rotundus L.)                                       Wild Oats         (Avena fatus)                                               Quackgrass        (Agropyron repens)                                          Field Bindweed    (Convolvulus arvensis L.)                                   Morningglory      (Ipomoea purpurea)                                          Velvetleaf        (Abutilon theophrasti)                                      Barley            (Hordeum vulgare)                                           Corn              (Zea mays)                                                  Green Foxtail     (Setaria viridis)                                           Wild Mustard      (Brassica kaber)                                            Sugar Beets       (Beta vulgaris)                                             Cotton            (Gossypium hirsutum)                                        Rice Paddy        (Oryza sativa)                                              ______________________________________                                    

Data obtained are reported in Table VI below.

    TABLE IV      POST-EMERGENCE TESTS - RATES IN KG/HA   BARN-     FLD MRN-   S     YARD GREEN P NUT WILD QUACK BIND GLRY WILD VELVET BARLY SUGAR CORN COT-     RICE Compound RATE GR FOX SEDGE OATS GRASS WD SP MUSTD LEAF LA BEETS     FIELD TON PADDY       2-Isopropyl-2-methyl-3-thio- 2.000 9.0 9.0 8.0 8.0 8.0 9.0 8.0 9.0 9.0 7     .0 9.0 9.0 8.0 3.0 5.sub.--H--imidazo[2,1-.sub.--α]isoindole-     1.000 9.0 9.0 5.5 8.0 8.0 8.5 8.0 9.0 8.0 7.0 9.0 9.0 8.0 1.0 3(2.sub.--H     ),5-dione .500 8.5 7.0 5.0 7.0 6.5 8.5 8.0 9.0 9.0 6.0 9.0 8.0 8.0 1.0     .250 5.0 3.0 4.0 3.0 4.0 8.5 6.0 9.0 7.0 4.0 9.0 9.0 8.0 0.0  .125 2.5     0.0 1.5 0.0 3.0* 6.0 3.0 9.0 3.0 3.0 9.0 7.0 6.0 1.0  .063 0.0 0.0 1.0     0.0 1.5 3.0 2.0 9.0 1.0 2.0 9.0 3.0 3.0 0.0 Isopropyl -o-(4-isopropyl-4-     2.000 0.0 0.0 0.0 0.0 0.0 0.0 5.0 6.0 0.0 0.0 9.0 0.0 7.0 0.0 methyl-5-th     ioxo-2-imidazo- 1.000 0.0 0.0 0.0 0.0 0.0 0.0 2.0 5.0 0.0 0.0 9.0 0.0     0.0 lin-2-yl)benzoate .500 0.0 0.0 0.0 0.0 0.0 0.0 2.0 3.0 0.0 0.0 6.0     0.0 7.0 0.0  .250 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.0 0.0 0.0 5.0 0.0  0.0     .125 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 0.0 7.0 0.0  .063 0.0     0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 0.0 6.0 0.0 Sodium -o-(4-isopropy     l-4- 1.000 9.0 6.0 6.0 9.0 3.0 9.0 7.0 9.0 9.0 9.0 9.0 9.0 6.0 0.0     methyl-5-thioxo-2-imidazo- .500 5.0 8.0 3.0 3.0 0.0 6.0 3.0 9.0 3.0 6.0     9.0 4.0 5.0 0.0 lin-2-yl)benzoate .250 3.0 6.0 2.0 0.0 0.0 5.0 2.0 9.0     0.0 4.0 9.0 3.0 3.0 0.0  .125 0.0 0.0 0.0 0.0 0.0 4.0 3.0 9.0 0.0 2.0     9.0 2.0 0.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 3.0 0.0 9.0 0.0 1.0 9.0 1.0     0.0 0.0 (.sub.--R)-(+)-2-isopropyl-2- 2.000 8.5 9.0 8.0 9.0 8.5 9.0 8.0     9.0 9.0 9.0 9.0 9.0 7.0 0.0 methyl-3-thio-5- 1.000 8.5 9.0 8.0 9.0 8.0     9.0 7.0 9.0 9.0 9.0 9.0 9.0 7.0 0.0 .sub.--H--imidazo[2,1-α]-isoind     ole- .500 7.5 9.0 8.0 6.0 8.0 9.0 7.0 9.0 7.0 9.0 9.0 9.0 7.0 0.0     3(2.sub.--H),5-dione .250 6.5 7.0 3.5 6.0 7.5 9.0 5.0 9.0 6.0 9.0 9.0     9.0 4.0 0.0  .125 3.0 7.0 5.5 3.0 8.0 9.0 3.0 9.0  9.0 9.0 9.0 5.0 0.0     .063 1.0 4.0 2.0 2.0 4.5 6.0 2.0 9.0 3.0 4.0 9.0 5.0 3.0 0.0 Calcium     -o-(4-isopropyl-4- 2.000 7.0 7.0 8.0 9.0 8.0 7.0 3.0 9.0 4.0 9.0 9.0 9.0     5.0 1.0 methyl-5-thioxo-2-imidazo- 1.000 7.0 7.0 7.0 7.0 8.0 9.0 2.0 9.0     3.0 9.0 9.0 7.0 5.0 0.0 lin-2-yl)benzoate .500 3.0 7.0 5.0 4.0 4.0 6.0     0.0 9.0 0.0 7.0 9.0 6.0 5.0 0.0  .250 0.0 3.0  0.0 9.0 3.0 0.0 9.0 0.0     6.0 9.0 7.0 3.0 0.0  .125 0.0 0.0 0.0 0.0 0.0 7.0 0.0 9.0 0.0 4.0 9.0     9.0 3.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 7.0 0.0 9.0 0.0 4.0 9.0 9.0 3.0     0.0 Methyl 2-(4-isopropyl-4- 2.000 4.0 0.0 0.0 9.0 0.0 6.0 0.0 9.0 2.0     0.0 9.0 3.0 0.0 0.0 methyl-5-thioxo-2-imidazo- 1.000 2.0 0.0 0.0 7.0 0.0     6.0 0.0 9.0 2.0 0.0 0.0 2.0 0.0 0.0 lin-2-yl)--p-toluate .500 0.0 0.0     0.0 7.0 0.0 3.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0  .250 0.0 0.0 0.0 6.0     0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0  .125 0.0 0.0 0.0 4.0 0.0 0.0     0.0 7.0 0.0 0.0 0.0 0.0 0.0 0.0  .063 0.0 0.0 0.0 2.0 0.0 0.0 0.0 6.0     0.0 0.0 0.0 0.0 0.0 0.0 2-Isopropyl-2,8-dimethyl- 2.000 0.0 0.0 0.0 9.0     0.0 9.0 0.0 9.0 0.0 6.0 9.0 3.0 2.0 3.0 3-thio-5.sub.--H--imidazo[2,1-.su     b.--α]- 1.000 0.0 0.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 3.0 9.0 2.0 0.0     2.0 isoindole-3(2.sub.--H),5-dione .500 0.0 0.0 0.0 9.0 0.0 6.0 0.0 9.0     0.0 3.0 9.0 1.0 0.0 2.0  .250 0.0 0.0 0.0 8.0 0.0 5.0 0.0 9.0 0.0 2.0     9.0 0.0 0.0 0.0  .125 0.0 0.0 0.0 7.0 0.0 5.0 0.0 9.0 0.0 1.0 9.0 0.0     0.0 0.0  .063 0.0 0.0 0.0 5.0 0.0  0.0 6.0 0.0 0.0 9.0 0.0 0.0 0.0     2-(4-Isopropyl-4-methyl-5- 2.000 0.0 2.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 4.0     9.0 3.0 4.0 3.0 thioxo-2-imidazolin-2-yl)- 1.000 0.0 0.0 0.0 9.0 0.0 9.0     0.0 9.0 0.0 3.0 9.0 0.0 3.0 4.0 -p-toluic acid .500 0.0 0.0 0.0 9.0 0.0     9.0 0.0 9.0 0.0 3.0 9.0 0.0 3.0 3.0  .250 0.0 0.0 0.0 9.0 0.0 9.0 0.0     9.0 0.0 2.0 9.0 0.0 2.0 3.0  .125 0.0 0.0 0.0 6.0 0.0 8.0 0.0 9.0 0.0     0.0 9.0 0.0 0.0 3.0  .063 0.0 0.0 0.0 5.0 0.0 6.0 0.0 7.0 0.0 0.0 9.0     0.0 0.0 3.0 Methyl 2-(4-isopropyl-4- 2.000 5.0 0.0 0.0 9.0 0.0 6.0 5.0     7.0 0.0 0.0 5.0 0.0 0.0 0.0 methyl-5-thioxo-2-imidazolin- 1.000 0.0 0.0     0.0 9.0 0.0 4.0 0.0 7.0 0.0 0.0  0.0 0.0 0.0 2-yl)--p-toluate and methyl     6- .500 0.0 0.0 0.0 7.0 0.0 0.0 0.0 6.0 0.0 0.0 4.0 0.0 0.0 0.0 (4-isopro     pyl-4-methyl-5- .250 0.0 0.0 0.0 7.0 0.0 0.0 0.0 5.0 0.0 0.0 2.0 0.0 0.0     0.0 thioxo-2-imidazolin-2-yl)- .125 0.0 0.0 0.0 5.0 0.0 0.0 0.0 6.0 0.0     0.0 2.0 0.0 0.0 0.0 --m-toluate .063 0.0 0.0 0.0 4.0 0.0 0.0 0.0 5.0 0.0     0.0 0.0 0.0 0.0 0.0 2-(4-Isopropyl-4-methyl-5- 2.000 0.0 0.0 0.0 9.0 0.0     9.0 0.0 9.0 0.0 6.0 9.0 3.0 3.0 0.0 thioxo-2-imidazolin-2-yl)- 1.000 0.0     0.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 3.0 9.0 2.0 3.0 0.0 -p-toluic acid and     6-(4-iso- .500 0.0 0.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 3.0 9.0 0.0 2.0 0.0     propyl-4-methyl-5-thioxo-2- .250 0.0 0.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 2.0     9.0 0.0 0.0 0.0 imidazolin-2-yl)---m-toluic .125 0.0 0.0 0.0 7.0 0.0 8.0     0.0 7.0 0.0 2.0 9.0 0.0 0.0 0.0 acid .063 0.0 0.0 0.0 4.0 0.0 7.0 0.0     5.0 0.0 1.0 9.0 0.0 0.0 0.0 6-(4-Isopropyl-4-methyl-5- 2.000 7.5 8.0 8.0     9.0 9.0 9.0 4.5 9.0 8.5 9.0 9.0 6.0 2.5 7.0 thioxo-2-imidazolin-2-yl)-     1.000 7.0 6.5 3.0 9.0 8.0 9.0 3.5 9.0 7.5 9.0 9.0 5.0 2.0 5.0 --m-toluic     acid .500 5.5 7.0 3.0 7.0 6.0 9.0 1.0 9.0 5.5 9.0 9.0 4.0 1.5 4.0  .250     2.0 5.5 0.0 7.0 3.0 9.0 0.0 9.0 3.0 8.0 9.0 3.0 1.0 4.0  .125 0.5 4.5     0.0 5.0 2.0 7.0 0.0 5.0 1.0 5.0 9.0 1.0 1.0 4.0  .063 0.5 3.5 0.0 0.0     0.0 7.0 0.0 0.0 0.0 3.0 9.0 1.0 0.5 2.0 Methyl 6-(4-isopropyl-4- 2.000     0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0 8.0 0.0 3.0 0.0 methyl-5-thioxo-2     -imidazo- 1.000 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0 6.0 0.0 2.0 0.0     lin-2-yl)---m-toluate .500 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0     0.0 2.0 0.0  .250 0.0 0.0 0.0 7.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 2.0     0.0  .125 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0  .063     0.0 0.0 0.0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 2-Isopropyl-2,7-d     imethyl-3- 2.000 5.0 7.0 7.0 7.0 8.0 9.0 5.0 9.0 9.0 7.0 9.0 3.0 5.0 6.0     thio-5.sub.--H--imidazo[2,1-α]isoin- 1.000 3.0 6.0 5.0 6.0 8.0 9.0     2.0 9.0 6.0 8.0 8.0 2.0 4.0 5.0 dole-3(2.sub.--H),5-dione .500 2.0 6.0     2.0 5.0 7.0 9.0 0.0 8.0 4.0 6.0 8.0 0.0 3.0 3.0  .250 0.0 5.0 0.0 3.0     4.0 7.0 0.0 6.0 3.0 4.0 9.0 0.0 2.0 3.0  .125 0.0 3.0 0.0 2.0 0.0 9.0     0.0 3.0 0.0 3.0 9.0 0.0 2.0 3.0  .063 0.0 2.0 0.0 0.0 0.0 3.0 0.0 0.0     0.0 2.0 9.0 0.0 2.0 2.0 9-Fluoro-1,9bα-dihydro-3 - 2.000 0.0 0.0     3.0 0.0 0.0 0.0 7.0 9.0 4.0 0.0 9.0 0.0 7.0 0.0 isopropyl-3-methyl-2-thio     - 1.000 0.0 0.0 2.0 0.0 0.0 0.0 7.0 8.0 2.0 0.0 9.0 0.0 5.0 0.0 5.sub.--H     --imidazo[2,1-.sub.--α]insoindole- .500 0.0 0.0 0.0 0.0 0.0 0.0     5.0 7.0 0.0 0.0 9.0 0.0 5.0 0.0 2(3.sub.--H),5-dione .250 0.0 0.0 0.0     0.0 0.0 0.0 3.0 6.0 0.0 0.0 7.0 0.0 4.0 0.0  .125 0.0 0.0 0.0 0.0 0.0     0.0 2.0 3.0 0.0 0.0 5.0 0.0 4.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0     3.0 0.0 0.0 3.0 0.0 3.0 0.0 9-Fluoro-2-isopropyl-2- 2.000 7.0 5.0 8.0     5.0 0.0 9.0 9.0 9.0 9.0 4.0 9.0 8.0 9.0 2.0 methyl-3-thio-5.sub.--H--imid     azo- 1.000 6.0 2.0 8.0 2.0 0.0 9.0 9.0 9.0 9.0 3.0 9.0 7.0 9.0 2.0     [2,1-α]isoindole-3(2.sub.--H),5- .500 2.0 0.0 8.0 0.0 0.0 9.0 8.0     9.0 9.0 2.0 9.0 6.0 9.0 2.0 dione .250 0.0 0.0 5.0 0.0 0.0 9.0 8.0 9.0     6.0 1.0 9.0 3.0 9.0 2.0  .125 0.0 0.0 5.0 0.0 0.0 7.0 8.0 9.0 6.0 1.0     9.0 2.0 7.0 2.0  .063 0.0 0.0 2.0 0.0 0.0 7.0 8.0 9.0 3.0 1.0 9.0 2.0     7.0 2.0 1,9bα-Dihydro-3 -isopropyl- 2.000  0.0  3.0 0.0 8.0 8.0     9.0 8.0 0.0 9.0 8.0 8.0 2.0 3-methyl-2-thio-5.sub.--H--imidazo- 1.000     2.0 0.0  2.0 0.0 8.0 8.0 9.0 8.0 0.0 9.0 6.0 8.0 2.0 [2,1-.sub.--α]i     soindole-2(3H),5- .500 0.0 0.0  2.0 0.0 7.0 8.0 9.0 7.0 0.0 9.0 6.0 7.0     2.0 dione .250 0.0 0.0 3.0 0.0 0.0 7.0 8.0 9.0 7.0 0.0 9.0 3.0 7.0 2.0     .125 0.0 0.0 2.0 0.0 0.0 7.0 8.0 9.0 3.0 0.0 9.0 2.0 7.0 2.0  .063 0.0     0.0 0.0 0.0 0.0 6.0 8.0 9.0 0.0 0.0 8.0 2.0 6.0 2.0 1,9bβ-Dihydro-3.     alpha.-isopropyl- 2.000 8.0 7.0 7.0 8.0 7.0 9.0 9.0 9.0 9.0 4.0 9.0 8.0     9.0 2.0 3-methyl-2-thio-5.sub.--H-imidazo- 1.000 7.0 3.0 7.0 6.0 0.0 9.0     8.0 9.0 9.0 2.0 9.0 7.0 8.0 2.0 [2,1-.sub.--α]isoindole-2(3.sub.--H     ),5- .500 3.0 0.0  3.0 0.0 9.0 9.0 9.0 9.0 2.0 9.0 6.0 8.0 2.0 dione     .250 2.0 0.0 3.0 0.0 0.0 7.0 8.0 9.0 9.0 0.0 9.0 5.0 8.0 2.0  .125 0.0     0.0 3.0 0.0 0.0 5.0 8.0 9.0 8.0 0.0 9.0 3.0 7.0 2.0  .063 0.0 0.0 0.0     0.0 0.0 5.0 8.0 9.0 7.0 0.0 9.0 2.0 7.0 2.0 3-Isopropyl-3-methyl-2-thio-     2.000 9.0 0.0 4.0 0.0 0.0 9.0 8.0 9.0 8.0 2.0 9.0 4.0 7.0 2.0 5.sub.--H--     imidazo[2,1-α]isoindole- 1.000 9.0 0.0 0.0 0.0 0.0 7.0 8.0 9.0 3.0     0.0 9.0 2.0 7.0 2.0 2(3.sub.--H),5-dione .500 9.0 0.0 0.0 0.0 0.0 5.0     8.0 9.0 5.0 0.0 9.0 2.0 7.0 2.0  .250 9.0 0.0 0.0 0.0 0.0 5.0 9.0 9.0 30     0.0 9.0 2.0 7.0 2.0  .125 9.0 0.0 0.0 0.0 0.0 5.0 7.0 9.0 0.0 0.0 8.0     0.0 6.0 2.0  .063 9.0 0.0 0.0 0.0 0.0 0.0 6.0 9.0 0.0 0.0 8.0 0.0 6.0     2.0 2-(4-Isopropyl-4-methyl- 2.000 0.0 0.0 0.0 0.0 0.0 2.0 2.0 3.0 2.0     0.0 8.0 0.0 0.0 0.0 5-thioxo-2-imidazolin-2- 1.000 0.0 0.0 0.0 0.0 0.0     0.0 0.0 2.0 0.0 0.0 8.0 0.0 0.0 0.0 yl)-4,6-dimethylbenzoic .500 0.0 0.0     0.0 0.0 0.0 0.0 0.0 3.0 0.0 0.0 8.0 0.0 0.0 0.0 acid .250 0.0 0.0 0.0     0.0 0.0 0.0 0.0 2.0 0.0 0.0 7.0 0.0 0.0 0.0  .125 0.0 0.0 0.0 0.0 0.0     0.0 0.0 2.0 0.0 0.0 7.0 0.0 0.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0     2.0 0.0 0.0  0.0 0.0 0.0 2-Isopropyl-7-methoxy-2- 2.000 0.0 0.0 0.0 0.0     0.0 0.0 0.0 0.0 0.0 0.0 8.0 0.0 0.0 0.0 methyl-3-thio-5.sub.--H-imidazo-     1.000 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.0 0.0 0.0 0.0 [2,1-.alpha     .]isoindole-3(2.sub.--H),5- .500 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     5.0 0.0 0.0 0.0 dione .250 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0     0.0 0.0 0.0  .125 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0     0.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     2-Isopropyl-2,6,8-trimethyl- 2.000 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     0.0 0.0 0.0 0.0 0.0 3-thio-5.sub.--H--imidazo[2,1-α]iso- 1.000 0.0     0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 indole-3(2.sub.--H),5     -dione .500 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     .250 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0  .125 0.0     0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0  .063 0.0 0.0 0.0     0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

EXAMPLE 19 Preemergence herbicidal evaluation of test compounds

The preemergence herbicidal activity of test compounds is determinedusing the procedure of Example 17, excepting that test compounds areapplied at rates of application between 0.063 and 2.0 kg/ha to soilcontaining seeds of test plant species. The rating system employed isthe same as that described in Example 16, and the plant species used areas follows:

    ______________________________________                                        Barnyardgrass     (Echinochloa crusgalli)                                     Purple Nutsedge   (Cyperus rotundus L.)                                       Wild Oats         (Avena fatus)                                               Quackgrass        (Agropyron repens)                                          Field Bindweed    (Convolvulus arvensis L.)                                   Morningglory      (Ipomoea purpurea)                                          Velvetleaf        (Abutilon theophrasti)                                      Barley            (Hordeum vulgare)                                           Corn              (Zea mays)                                                  Green Foxtail     (Setaria viridis)                                           Wild Mustard      (Brassica kaber)                                            Sugar Beets       (Beta vulgaris)                                             Cotton            (Gossypium hirsutum)                                        Rice Paddy        (Oryza sativa)                                              ______________________________________                                    

Data obtained are reported in Table V below.

    TABLE V      PRE-EMERGENCE TESTS - RATES IN KG/HA   BARNY GREEN P NUT WILD QUACK FLD     B MRNGL WILD VELVE S BAR SUGAR CORN COTTO RICE Compound RATE ARDGR FOX     SEDGE CATS GRASS INDWD RY SP MUSTD TLEAF LY LA BEETS FIELD N PADDY       2-Isopropyl-2-methyl-3-thio- 2.000 9.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9     .0 9.0 9.0 8.0 9.0 5.sub.--H--imidazo[2,1-.sub.--α]isoindole-     1.000 9.0 9.0 9.0 4.0 9.0 9.0 8.0 9.0 8.0 6.0 9.0 9.0 8.0 7.5 3(2.sub.--H     ),5-dione .500 7.5 9.0 9.0 6.0 9.0 9.0 8.0 9.0 8.0 4.0 9.0 9.0 8.0 8.0     .250 4.5 6.0 9.0 2.0 9.0 9.0 6.0 9.0 6.0 3.0 9.0 5.0 4.0 7.0  .125 1.5     4.0 9.0 0.0 7.0 7.3 3.0 8.0 6.0 3.0 9.0 4.0 5.0 4.5  .063 0.0 0.0 7.0     0.0 4.7 5.7 2.0 8.0 3.0 2.0 9.0 3.0 2.0 1.0 Isopropyl - o-(4-isopropyl-4-      2.000 0.0 0.0 6.0 0.0 9.0 0.0 3.0 7.0 3.0 0.0 9.0 0.0 8.0 0.0 methyl-5-t     hioxo-2-imidazo- 1.000 0.0 0.0 3.0 0.0 9.0 0.0 3.0 0.0 2.0 0.0 9.0 0.0     8.0 0.0 lin-2-yl)benzoate .500 0.0 0.0 3.0 0.0 9.0 0.0 3.0 0.0 0.0 0.0     8.0 0.0 8.0 0.0  .250 0.0 0.0 3.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 8.0 0.0     7.0 0.0  .125 0.0 0.0 2.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 7.0 0.0  0.0  .063     0.0 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 3.0 0.0 3.0 0.0 Sodium -o-(4-isop     ropyl-4- 2.000 9.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 9.0 9.0 7.0 8.0     methyl-5-thioxo-2-imidazo- 1.000 6.0 9.0 9.0 6.0 9.0 9.0 8.0 9.0 6.0 9.0     9.0 9.0 7.0 7.5 lin-2-yl)benzoate .500 3.0 9.0 9.0 6.0 9.0 9.0 5.0 9.0     7.0 6.0 9.0 9.0 5.0 6.0  .250 0.0 5.0 9.0 5.0 9.0 8.5 3.0 9.0 5.0 5.0     9.0 8.0 4.0 3.5  .125 0.0 0.0 7.0 0.0 9.0 9.0 3.0 9.0 3.0 4.0 9.0 7.0     3.0 2.0  .063 0.0 0.0 1.5 0.0 6.5 7.0 0.0 9.0 0.0 2.0 9.0 3.0 2.0 0.0     .032   2.0  2.0 5.0        0.0 (.sub.--R)--(+)-2-isopropyl-2-methyl-     2.000 8.5 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 3-thio-5-.s     ub.--H-imidazo[2,1α]- 1.000 6.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 8.0     9.0 9.0 9.0 7.0 8.0 isoindole-3(2.sub.--H),5-dione .500 4.5 9.0 9.0 5.0     9.0 9.0 6.0 9.0 7.0 6.0 9.0 9.0 6.0 7.0  .250 4.5* 5.0 9.0 5.0 9.0 9.0     4.0 9.0 5.0 4.0 9.0 9.0 5.0 6.5  .125 1.0 0.0 8.3 0.0 9.0 9.0 0.0 8.0     2.0 3.0 9.0 6.0 5.0 3.5  .063 0.0 0.0 8.0 0.0 3.7 7.7 0.0 7.0 0.0 2.0     9.0 3.0 4.0 3.5  .032   2.0  0.0 0.0        0.0 Calcium -o-(4-isopropyl-4     - 2.000 6.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 methyl-5-     thioxo-2-imidazo- 1.000 4.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 8.0 9.0 9.0 9.0     8.0 6.0 lin-2-yl)benzoate .500 3.0 9.0 9.0 5.0 9.0 9.0 6.0 9.0 7.0 9.0     9.0 9.0 6.0 5.0  .250 2.0 5.0 8.0 0.0 9.0 8.0 5.0 9.0 3.0 3.0 9.0 7.0     4.0 0.5  .125 0.0 0.0 8.0 0.0 5.5 5.0 3.0 9.0 2.0 4.0 9.0 6.0 3.0 0.0     .063 0.0 0.0 5.5 0.0 4.0 6.0 2.0 7.0 0.0 2.0 9.0 4.0 2.0 0.0  .032   0.0      2.0 2.0        0.0 Methyl 2-(4-isopropyl-4- 2.000 8.0 7.0 5.0 8.0 0.0     9.0 5.0 9.0 8.0 2.0 9.0 0.0 4.0 0.0 methyl-5-thioxo-2-imidazo- 1.000 8.0     7.0 5.0 9.0 0.0 9.0 3.0 9.0 6.0 0.0 9.0 0.0 2.0 0.0 lin-2-yl)--p-toluate     .500 6.0 4.0 0.0 9.0 0.0 8.0 0.0 9.0 3.0 0.0 2.0 0.0 0.0 0.0  .250 2.0     0.0 0.0 9.0 0.0 9.0 0.0 9.0 0.0 0.0 2.0 0.0 0.0 0.0  .125 2.0 0.0 0.0     6.0 0.0 0.0 0.0 7.0 0.0 0.0 2.0 0.0 0.0 0.0  .063 0.0 0.0 0.0 4.0 0.0     0.0 0.0 3.0 0.0 0.0  0.0 0.0 0.0 2-Isopropyl-2,8-dimethyl- 2.000 7.0 9.0     8.0 9.0 9.0 9.0 6.0 9.0 8.0 7.0 9.0 5.0 7.0 9.0 3-thio-5.sub.--H-imidazo[     2,1-.sub.--α]- 1.000 7.0 6.0 9.0 6.0 4.0 9.0 5.0 6.0 8.0 6.0 9.0     2.0 6.0 9.0 isoindole-3(2-- H),5-dione .500 3.0 4.0 2.0 3.0 0.0 9.0 0.0     4.0 2.0 9.0 1.0 4.0 4.0  .250 0.0 0.0 0.0 2.0 0.0 8.0 0.0 4.0 0.0 1.0     9.0 0.0 1.0 1.0  .125 0.0 0.0 0.0 0.0 0.0 7.0 0.0  0.0 0.0 9.0 0.0 0.0     0.0  .063 0.0 0.0 0.0 0.0 0.0 7.0 0.0  0.0 0.0 9.0 0.0 0.0 0.0 2-(4-Isopr     opyl-4-methyl-5- 2.000 9.0 9.0 8.0 9.0 9.0 9.0 6.0 9.0 9.0 6.0 9.0 5.0     6.0 9.0 thioxo-2-imidazolin-2-yl)- 1.000 5.0 3.0 8.0 9.0 0.0 9.0 3.0 9.0     5.0 4.0 9.0 2.0 4.0 9.0 .sub.--p-toluic acid .500 0.0 0.0 2.0 7.0 0.0     8.0 0.0 9.0 4.0 3.0  1.0 2.0 6.0  .250 0.0 0.0 3.0 3.0 0.0 8.0 0.0 7.0     0.0 2.0 9.0 0.0 0.0 3.0  .125 0.0 0.0 0.0 0.0 0.0 8.0 0.0 7.0 0.0 0.0     9.0 0.0 0.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 4.0 0.0 4.0 0.0 0.0 5.0 0.0     0.0 0.0 Methyl 2-(4-isopropyl-4- 2.000 9.0 6.0 6.0 9.0 2.0 9.0 2.0 9.0     8.0 0.0 9.0 0.0 0.0 3.0 methyl-5-thioxo-2-imidazolin- 1.000 7.0 2.0 2.0     8.0 0.0 9.0 0.0 9.0 7.0 0.0 9.0 0.0 0.0 2.0 2-yl)--p-toluate and methyl     6- .500 6.0 0.0 0.0 7.0 0.0 9.0 0.0 9.0 2.0 0.0 4.0 0.0 0.0 0.0 (4-isopro     pyl-4-methyl-5- .250 2.0 0.0 0.0 6.0 0.0 8.0 0.0 8.0 0.0 0.0 2.0 0.0 0.0     0.0 thioxo-2-imidazolin-2-yl)- .125 0.0 0.0 0.0 6.0 0.0 3.0 0.0  0.0 0.0      0.0 0.0 0.0 .sub.--m-toluate .063 0.0 0.0 0.0 3.0 0.0  0.0 4.0 0.0 0.0     2.0 0.0 0.0 0.0 2-(4-Isopropyl-4-methyl-5- 2.000 6.0 6.0 9.0 9.0 9.0 9.0     7.0 9.0 9.0 6.0 9.0 6.0 6.0 7.0 thioxo-2-imidazolin-2-yl)- 1.000 8.0 7.0     9.0 6.0 9.0 9.0 5.0 9.0 8.0 6.0 9.0 4.0 5.0 9.0 -p-toluic acid and     6-(4-iso- .500 2.0 6.0 6.0 0.0 2.0 9.0 3.0 5.0 7.0 3.0 9.0 2.0 4.0 6.0     propyl-4-methyl-5-thioxo-2- .250 0.0 2.0 4.0 0.0 0.0 9.0 0.0 4.0 2.0 1.0     9.0 0.0 2.0 5.0 imidazolin-2-yl)-.sub.--m-toluic .125 0.0 0.0 0.0 0.0     0.0 7.0 0.0 4.0 0.0 0.0 3.0 0.0 7.0 3.0 acid .063 0.0 0.0 0.0 0.0 0.0     6.0 0.0 3.0 0.0 0.0 8.0 0.0  2.0 6-(4-Isopropyl-4-methyl-5- 2.000 8.0     9.0 9.0 7.0 9.0 9.0 7.0 7.0 8.0 8.0 9.0 9.0 6.0 8.0 thioxo-2-imidazolin-2     -yl)- 1.000 6.0 9.0 9.0 4.0 9.0 8.0 6.0 4.0 7.0 4.0 9.0 4.0 5.0 8.0     .sub.--m-toluic acid .500 4.0 7.0 9.0 3.0 9.0 7.0 3.0 4.0 6.0 5.0 9.0     3.0 6.0 8.0  .250 3.0 6.0 8.0 0.0 9.0 7.0  3.0 4.0 3.0 9.0 2.0 3.0 6.0     .125 0.0 5.0 3.0 0.0 0.0 3.0 0.0 0.0 3.0 0.0 9.0 0.0 2.0 3.0  .063 0.0     5.0 3.0 0.0  3.0 0.0 0.0 0.0 0.0 9.0 0.0 0.0 3.0 Methyl 6-(4-isopropyl-4-      2.000 5.0 0.0 3.0 7.0 0.0 8.0 4.0 0.0 5.0 0.0 9.0 0.0 0.0 4.0 methyl-5-t     hioxo-2-imidazo- 1.000 3.0 0.0 2.0 7.0 0.0 4.0 2.0 0.0 2.0 0.0 9.0 0.0     0.0 3.0 lin-2-yl)-.sub.--m-toluate .500 3.0 0.0 2.0 7.0 0.0 3.0 2.0 0.0     0.0 0.0 9.0 0.0 0.0 2.0  .250 3.0 0.0 0.0 7.0 0.0 0.0 0.0 0.0 0.0 0.0     7.0 0.0 0.0 2.0  .125 0.0 0.0 0.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 8.0 0.0     0.0 0.0  .063 0.0 0.0 0.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0  0.0 0.0 0.0     2-Isopropyl-2,7-dimethyl-3- 2.000 8.0 9.0 9.0 7.0 9.0 9.0 8.0 8.0 8.0     8.0 9.0 6.0 6.0 9.0 thio-5.sub.--H--imidazo[2,1-α]isoin- 1.000 8.0     9.0 9.0 5.0 9.0 9.0 6.0 7.0 8.0 9.0 9.0 5.0 3.0 8.0 dole-3(2H),5-dione     .500 5.0 6.0 7.0 3.0 9.0 9.0 5.0 5.0 6.0 5.0 9.0 4.0 3.0 6.0  .250 2.0     6.0 6.0 0.0 4.0 7.0 5.0 2.0 5.0 4.0 9.0 3.0  5.0  .125 2.0 6.0 6.0 0.0     6.0 3.0 2.0 5.0 3.0 9.0 3.0 2.0 4.0  .063 0.0 6.0 3.0 0.0 0.0 4.0 2.0     0.0 3.0 0.0 9.0 0.0 3.0 3.0 9-Fluoro-1,9bα-dihydro-3- 2.000 5.0     0.0 9.0 0.0 0.0 9.0 8.0 9.0 8.0 0.0 9.0 0.0 7.0 0.0 isopropyl-3-methyl-2-     thio- 1.000 2.0 0.0 6.0 0.0 0.0 9.0 8.0 9.0 7.0 0.0 9.0 0.0 7.0 0.0     5H--imidazo[2,1-α]isoindole- .500 0.0 0.0 6.0 0.0 0.0 9.0 8.0 8.0     8.0 0.0 9.0 0.0 6.0 0.0 2(3H),5-dione .250 0.0 0.0 4.0 0.0 0.0 9.0 8.0     7.0 2.0 0.0 9.0 0.0 4.0 0.0  .125 0.0 0.0 2.0 0.0 0.0 9.0 8.0 7.0 0.0     0.0 9.0 0.0 5.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 8.0 8.0 6.0 0.0 0.0 9.0     0.0 4.0 0.0 9-Fluoro-2-isopropyl-2- 2.000 8.0 9.0 9.0 7.0 9.0 9.0 8.0     9.0 8.0 7.0 9.0 8.0 9.0 9.0 methyl-3-thio-5H-imidazo- 1.000 8.0 7.0 9.0     6.0 9.0 9.0 8.0 9.0 8.0 3.0 9.0 7.0 9.0 9.0 [2,1-α]isoindole-3(2H),     5- .500 6.0 7.0 9.0 4.0 9.0 9.0 8.0 8.0 8.0 7.0 9.0 5.0 8.0 4.0 dione     .250 2.0 4.0 9.0 3.0 7.0 9.0 8.0 8.0 8.0 2.0 9.0 4.0 8.0 3.0  .125 0.0     0.0 9.0 0.0 7.0 8.0 8.0 8.0 7.0 0.0 9.0 2.0 7.0 0.0  .063 0.0 0.0 9.0     0.0 3.0 9.0 8.0 8.0 5.0 0.0 9.0 2.0 7.0 0.0 1,9bα-Dihydro-3-isoprop     yl- 2.000 8.0 7.0 9.0 5.0 9.0 9.0 8.0 9.0 8.0 3.0 9.0 4.0 7.0 5.0     3-methyl-2-thio-5H-imidazo- 1.000 7.0 5.0 9.0 3.0 9.0 9.0 8.0 9.0 7.0     2.0 9.0 2.0 7.0 5.0 [2,1-.sub.--α]isoindole-2(3H),5- .500 4.0 6.0     8.0 0.0 6.0 9.0 6.0 8.0 7.0 0.0 9.0 2.0 7.0 3.0 dione .250 2.0 2.0 8.0     0.0 3.0 8.0 5.0 8.0 3.0 0.0 9.0 0.0 7.0 3.0  .125 0.0 0.0 7.0 0.0 0.0     8.0 5.0 8.0 0.0 0.0 9.0 0.0 6.0 0.0  .063 0.0 0.0 7.0 0.0 0.0 8.0 6.0     9.0 0.0 0.0 9.0 0.0 6.0 0.0 1,9bβ-Dihydro-3α-isopropyl- 2.000     8.0 8.0 9.0 7.0 9.0 9.0 7.0 9.0 8.0 6.0 9.0 3.0 8.0 2.0 3-methyl-2-thio-5     H-imidazo- 1.000 8.0 8.0 9.0 7.0 9.0 9.0 8.0 9.0 8.0 6.0 9.0 3.0 8.0 2.0     [2,1-.sub.--α]isoindole-2(3.sub.--H),5- .500 8.0 9.0 8.0 5.0 8.0     9.0 8.0 9.0 7.0 5.0 9.0 2.0 8.0 2.0 dione .250 6.0 7.0 5.0 2.0 7.0 8.0     7.0 8.0 5.0 2.0 9.0 0.0 7.0 2.0  .125 0.0 0.0 5.0 0.0 5.0 9.0  8.0 2.0     0.0 9.0 0.0 6.0 2.0  .063 0.0 0.0 2.0 0.0 0.0 7.0 7.0 8.0 2.0 0.0 9.0     0.0 4.0 2.0 3-Isopropyl-3-methyl-2-thio- 2.000 5.0 0.0 9.0 0.0 0.0 8.0     7.0 9.0 7.0 0.0 9.0 0.0 6.0 0.0 5.sub.--H-imidazo[2,1-α]isoindole-     1.000 0.0 0.0 8.0 0.0 0.0 7.0 7.0 8.0 6.0 0.0 9.0 0.0 3.0 0.0 2(3H),5-dio     ne .500 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.0 0.0 0.0 7.0 0.0 2.0 0.0  .250     0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0 6.0 0.0 0.0 0.0  .125 0.0 0.0     0.0 0.0 0.0 0.0 0.0  0.0 0.0 6.0 0.0 0.0 0.0  .063 0.0 0.0 0.0 0.0 0.0     0.0 0.0  0.0 0.0  0.0  0.0 2-(4-Isopropyl-4-methyl- 2.000 9.0 9.0 9.0     4.0 7.0 9.0 8.0 9.0 8.0 3.0 9.0 3.0 9.0 3.0 5-thioxo-2-imidazolin-2-     1.000 7.0 9.0 9.0 2.0  9.0 7.0 9.0 8.0 3.0 9.0 2.0 8.0 2.0 yl)-4,6-dimeth     ylbenzoic .500 3.0 9.0 9.0 0.0 3.0 8.0 6.0 9.0 8.0 0.0 9.0 2.0 7.0 0.0     acid .250 2.0 5.0 7.0 0.0 2.0 7.0 5.0 9.0 6.0 0.0 9.0 0.0 5.0 0.0  .125     0.0 0.0 0.0 0.0 0.0 3.0 2.0 6.0 3.0 0.0 9.0 0.0  0.0  .063 0.0 0.0 0.0     0.0 0.0 0.0 0.0 6.0 2.0 0.0 9.0 0.0  0.0 2-Isopropyl-7-methoxy-2- 2.000     8.0 9.0 9.0 8.0 9.0 9.0 8.0 8.0 9.0 9.0 9.0 8.0 7.0 9.0 methyl-3-thio-5H-     imidazo- 1.000 8.0 9.0 7.0 7.0 9.0 7.0 7.0 9.0 8.0 3.0 9.0 6.0 7.0 9.0     [2,1-α]isoindole-3(2H),5- .500 6.0 9.0 7.0 2.0 9.0 7.0 5.0 6.0 8.0     3.0 9.0 5.0 6.0 8.0 dione .250 0.0 7.0  0.0 7.0 5.0 3.0  7.0 0.0 9.0 4.0     5.0 7.0  .125 0.0 5.0 3.0 0.0  2.0 0.0 3.0 3.0 0.0 9.0 2.0 4.0 2.0  .063     0.0 0.0 3.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9.0 0.0 3.0 2.0 2-Isopropyl-2,6,8     -trimethyl- 2.000 7.0 9.0 9.0 0.0 0.0 8.0 8.0 9.0 8.0 2.0 9.0 3.0 7.0     2.0 3-thio-5.sub.--H-imidazo[2,1-α]iso- 1.000 5.0 9.0 8.0 0.0 0.0     7.0 8.0 9.0 7.0 2.0 9.0 2.0 7.0 2.0 indole-3(2.sub.--H),5-dione .500 3.0     7.0 5.0 0.0 0.0 3.0 5.0 8.0 5.0 0.0 9.0 0.0 6.0 0.0  .250 0.0 6.0 5.0     0.0 0.0  2.0 7.0 3.0 0.0 9.0 0.0 6.0 0.0  .125 0.0 5.0 0.0 0.0 0.0 0.0     0.0 0.0 0.0 0.0 9.0 0.0 5.0 0.0  .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0     0.0 0.0 9.0 0.0 2.0 0.0

What we claim is:
 1. A compound having the structure: ##STR33## whereinR₁ and R₂ each represent C₁ -C₃ alkyl or cyclopropyl, with the provisothat the sum of the number of carbon atoms in R₁ and R₂ is 2 to 5; andwhen R₁ and R₂ are taken together with the carbon to which they areattached, they may form a C₃ -C₆ cycloalkyl ring optionally substitutedwith methyl;X is hydrogen, halogen or methyl; Y and Z are each hydrogen,halogen, C₁ -C₆ alkyl, C₁ -C₄ hydroxyalkyl, C₁ -C₆ alkoxy, C₁ -C₄alkylthio, phenoxy, C₁ -C₄ haloalkyl, OCF₂ CHF₂, OCF₃, OCHF₂, nitro,cyano, NR₄ R₅, C₃ -C₈ straight or branched alkenyloxy optionallysubstituted with one to three halogens, C₃ -C₈ straight or branchedalkynyloxy optionally substituted with one to three halogens, or phenyloptionally substituted with one C₁ -C₄ alkyl, C₁ -C₄ alkoxy or halogen;R₃ is hydrogen, halogen, C₁ -C₄ alkyl, C₁ -C₄ alkylthio, C₁ -C₄ alkoxy,CF₃, NO₂, OCF₃, OCHF₂ or OCF₂ CHF₂ ; R₄ is hydrogen or C₁ -C₄ alkyl; R₅is C₁ -C₄ alkyl; And, when taken together, Y and Z may form a ring inwhich YZ is represented by (1) the structure: -(CH₂)_(n) -, where n isan integer of 2, 3 or 4; or (2) by the structure: ##STR34## where, L, M,R₇ and R₈ each represent hydrogen, halogen, C₁ -C₄ alkyl or C₁ -C₃alkoxy, and X is hydrogen; or when R₁ and R₂ are not the same, theoptical isomer thereof.
 2. A compound according to claim 1 wherein R₁ isCH₃ ; R₂ is CH(CH₃)₂ ; X, Y, Z and R₃ each represent hydrogen, halogen,C₁ -C₃ alkoxy or C₁ -C₃ alkyl; or the optical isomer thereof. 3.Compound according to claim1:(R)-(+)-2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]-isoindole-3(2H),5-dione;2-isopropyl-2,7-dimethyl-3-thio-5H-imidazo[2,1-a]-isoidole-3-(2H),5-dione; or2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]isoindole-3(2H), 5-dione.4. A herbicidal composition comprising an inert diluent and aherbicidally effective amount of a compound of the structure: ##STR35##wherein R₁ and R₂ each represent C₁ -C₃ alkyl or cyclopropyl, with theproviso that the sum of the number of carbon atoms in R₁ and R₂ is 2 to5; and when R₁ and R₂ are taken together with the carbon to which theyare attached, they may form a C₃ -C₆ cycloalkyl ring optionallysubstituted with methyl;X is hydrogen, halogen or methyl; PG,94 Y and Zare each hydrogen, halogen, C₁ -C₆ alkyl, C₁ -C₄ hydroxyalkyl, C₁ -C₆alkoxy, C₁ -C₄ alkylthio, phenoxy, C₁ -C₄ haloalkyl, OCF₂ CHF₂, OCF₃,OCHF₂, nitro, cyano, NR₄ R₅, C₃ -C₈ straight or branched alkenyloxyoptionally substituted with one to three halogens, C₃ -C₈ straight orbranched alkynyloxy optionally substituted with one to three halogens,or phenyl optionally substituted with one C₁ -C₄ alkyl, C₁ -C₄ alkoxy orhalogen; R₃ is hydrogen, halogen, C₁ -C₄ alkyl, C₁ -C₄ alkylthio, C₁ -C₄alkoxy, CF₃, NO₂, OCF₃, OCHF₂ or OCF₂ CHF₂ ; R₄ is hydrogen or C₁ -C₄alkyl; R₅ is C₁ -C₄ alkyl; And, when taken together, Y and Z may form aring in which YZ is represented by (1) the structure: -(CH₂)_(n) -,where n is an integer of 2, 3 or 4; or (2) by the structure: ##STR36##where, L, M, R₇ and R₈ each represent hydrogen, halogen, C₁ -C₄ alkyl orC₁ -C₃ alkoxy, and X is hydrogen;or when R₁ and R₂ are not the same, theoptical isomer thereof.
 5. A method for the control of undesirablemonocotyledonous and dicotyledonous plant species comprising applying tothe foliage of the plants or to soil containing seeds or otherpropagating organs thereof, a herbicidally effective amount of acompound having the structure: ##STR37## wherein R₁ and R₂ eachrepresent C₁ -C₃ alkyl or cyclopropyl, with the proviso that the sum ofthe number of carbon atoms in R₁ and R₂ is 2 to 5; and when R₁ and R₂are taken together with the carbon to which they are attached, they mayform a C₃ -C₆ cycloalkyl ring optionally substituted with methyl;X ishydrogen, halogen or methyl; Y and Z are each hydrogen, halogen, C₁ -C₆alkyl, C₁ -C₄ hydroxyalkyl, C₁ -C₆ alkoxy, C₁ -C₄ alkylthio, phenoxy, C₁-C₄ haloalkyl, OCF₂ CHF₂, OCF₃, OCHF₂, nitro, cyano, NR₄ R₅, C₃ -C₈straight or branched alkenyloxy optionally substituted with one to threehalogens, C₃ -C₈ straight or branched alkynyloxy optionally substitutedwith one to three halogens, or phenyl optionally substituted with one C₁-C₄ alkyl, C₁ -C₄ alkoxy or halogen; R₃ is hydrogen, halogen, C₁ -C₄alkyl, C₁ -C₄ alkylthio, C₁ -C₄ alkoxy, CF₃, NO₂, OCF₃, OCHF₂ or OCF₂CHF₂ ; R₄ is hydrogen or C₁ -C₄ alkyl; R₅ is C₁ -C₄ alkyl; And, whentaken together, Y and Z may form a ring in which YZ is represented by(1) the structure: -(CH₂)_(n) -, where n is an integer of 2, 3 or 4; or(2) by the structure: ##STR38## where, L, M, R₇ and R₈ each representhydrogen, halogen, C₁ -C₄ alkyl or C₁ -C₃ alkoxy, and X is hydrogen;orwhen R₁ and R₂ are not the same, the optical isomer thereof.
 6. A methodaccording to claim 5, wherein the compoundis:(R)-(+)-2-isopropyl-2-methyl-3-thio-5H-imidazo[2,1-a]-isoindole-3(2H),5-dione;2-isopropyl-2,7-dimethyl-3-thio-5H-imidazo[2,1-a]-isoindole-3-(2H),5-dione; or
 7. A method according to claim 6, wherein the compound isapplied to the foliage of the plants at a rate of from 0.032 to 8.0kg/ha.
 8. A method according to claim 6, wherein said compound isapplied to soil containing seed or other propagating organs ofundesirable plants at a rate between about 0.032 and 8.0 kg/ha.